A survey sampled men and women workers and asked if they expected to get a raise or promotion this year. Suppose the survey sampled 200 men and 200 women. If 98 of the men replied Yes and 72 of the women replied Yes, are the results statistically significant so that you can conclude a greater proportion of men expect to get a raise or a promotion this year?
a. State the hypothesis test in terms of the population proportion of men and the population proportion of women.
b. What is the sample proportion for men? For women?
c. Use α= 0.01 level of significance. What is the p-value and what is your conclusion?
Answer:
a)
The null hypothesis is: [tex]H_0: p_M - p_W = 0[/tex]
The alternative hypothesis is: [tex]H_1: p_M - p_W > 0[/tex]
b) For men is of 0.49 and for women is of 0.36.
c) The p-value of the test is 0.0039 < 0.01, which means that the results are statistically significant so that you can conclude a greater proportion of men expect to get a raise or a promotion this year.
Step-by-step explanation:
Before solving this question, we need to understand the central limit theorem and subtraction of normal variables.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
Men:
98 out of 200, so:
[tex]p_M = \frac{98}{200} = 0.49[/tex]
[tex]s_M = \sqrt{\frac{0.49*0.51}{200}} = 0.0353[/tex]
Women:
72 out of 200, so:
[tex]p_W = \frac{72}{200} = 0.36[/tex]
[tex]s_W = \sqrt{\frac{0.36*0.64}{200}} = 0.0339[/tex]
a. State the hypothesis test in terms of the population proportion of men and the population proportion of women.
At the null hypothesis, we test if the proportion are similar, that is, if the subtraction of the proportions is 0, so:
[tex]H_0: p_M - p_W = 0[/tex]
At the alternative hypothesis, we test if the proportion of men is greater, that is, the subtraction is greater than 0, so:
[tex]H_1: p_M - p_W > 0[/tex]
b. What is the sample proportion for men? For women?
For men is of 0.49 and for women is of 0.36.
c. Use α= 0.01 level of significance. What is the p-value and what is your conclusion?
From the sample, we have that:
[tex]X = p_M - p_W = 0.49 - 0.36 = 0.13[/tex]
[tex]s = \sqrt{s_M^2+s_W^2} = \sqrt{0.0353^2 + 0.0339^2} = 0.0489[/tex]
The test statistic is:
[tex]z = \frac{X - \mu}{s}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, and s is the standard error, so:
[tex]z = \frac{0.13 - 0}{0.0489}[/tex]
[tex]z = 2.66[/tex]
P-value of the test and decision:
The p-value of the test is the probability of finding a difference above 0.13, which is the p-value of z = 2.66.
Looking at the z-table, z = 2.66 has a p-value of 0.9961.
1 - 0.9961 = 0.0039.
The p-value of the test is 0.0039 < 0.01, which means that the results are statistically significant so that you can conclude a greater proportion of men expect to get a raise or a promotion this year.
HELP PLEASE BE CORRECT
Answer:
12
Step-by-step explanation:
Scale factor of 4
CD = 3
3 · 4 = 12
Length of C'D' is 12 units
Answer:
12 units
Step-by-step explanation:
The original segment CD = 3 units
Scale factor is 4.
3 x 4 = 12
I don’t know what this is I took a picture of it here.
Use the figure to find y.
Tanθ =sin /cos
tan θ = 5/2 / y
tan (30°) = 5/2 /y
[tex]y = \frac{5 \sqrt{3} }{2} [/tex]
y=4.33
URGENT!!!!!! 15 POINTDS
Answer:
Option C
Step-by-step explanation:
thankful that there are graphing tools. see screenshot
A survey is created to measure dietary habits. The survey asks questions about each meal and snack consumed for each day of the week. The survey seems like a good representation of measuring dietary habits. This survey would be considered to have high ______ validity.
Answer:
Face validity
Step-by-step explanation:
In quantitative research in mathematics, we have four major types of validity namely;
- Content Validity
- Construct validity
- Criterion validity
- Face validity.
Now;
> Construct validity seeks to find out if the tool used in measurement is a true representation of what is really going to be measured.
> Content Validity seeks to find out whether a test covers every part of a particular subject being tested.
> Face validity seeks to find out how true a test is by looking at it on the surface.
> Criterion validity seeks to find out the relationship of a particular test to that of another test.
Now, in this question, we are told that The survey seems like a good representation of measuring dietary habits after just asking questions about each meal and snack they consumed for the week. Thus, it is a face validity because it just appears true on the surface to be a good representation but we don't know if it is effective until we go deep like content validity
Hi please somebody help me with this equation with explanation thank you
Answer:
[tex]{ \tt{ \frac{1}{24} m - \frac{2}{3} = \frac{3}{4} }} \\ \\ { \tt{ \frac{1}{24} m = \frac{17}{12} }} \\ m = 34[/tex]
Step 1: Find a common denominator
---The common denominator here is 24. So, we need to transform all of the fractions to have a denominator of 24.
1/24m - 16/24 = 18/24
Step 2: Solve
1/24m - 16/24 = 18/24
1/24m = 34/24
m = 34/24 x 24/1
m = 34
Hope this helps!
15. What is the solution to k+(-12) = 42? (1 point)
k=-54
k=-30
k= 30
k=54
Answer:
k = 54
Step-by-step explanation:
k + (-12) = 42
Remove parenthesis and addition sign
k - 12 = 42
Add 12 to both sides
K = 54
[tex]\boxed{\large{\bold{\textbf{\textsf{{\color{blue}{Answer}}}}}}:)}[/tex]
k+(-12)=42k-12=42k=42+12k=54Help me! Thanks! Show work too! Please!
Answer:
(2, 79) (12, 24)
24-79/12-2=-55/10
m=-0.55
24=-6,6+b
30.6=b
y=-0.55x+30.6
Step-by-step explanation:
you multiply
using the equation to represent your answer
The gross domestic product (GDP) of the United States is defined as
Answer:
the market value of all final goods and services produced within the United States in a given period of time.
QUESTION 20
The patient's weight is 245 lbs. If the patient loses 1 kg every week for 5 weeks:
a. How much will the patient weight in pounds?
b. How much will the patient weight in kilograms?
.Answer:
The answer is below
Step-by-step explanation:
The patient loses 1 kg every week for 5 weeks.
1 kg = 2.2 lbs
Therefore the patient loses 2.2 lbs every week for 5 weeks.
a) The weight of the patient after 5 weeks = 245 lbs. - (5 weeks)(2.2 lbs per week)
The weight of the patient after 5 weeks = 245 lbs. - 11 lbs. = 234 lbs.
b) The weight of the patient after 5 weeks = 245 lbs. - 11 lbs. = 234 lbs.
1 kg = 2.2 lbs.
234 lbs. = 234 lbs. * 1 kg per 2.2 lbs. = 106.36 kg
what's a divisor a dividend and a quotient
Look at the figure below: an image of a right triangle is shown with an angle labeled y degrees If sin y° = s divided by 8 and tan y° = s divided by t, what is the value of cos y°?
cos y° = 8s
cos y° = 8t
cos y°= t / 8
cos y°=8 / t
Answer:
Cos y = t / 8
Step-by-step explanation:
Using the hints given in the question, the omitted tribagke will look like the triangle attached on the picture ;
From trigonometry :
Sin y = opposite / hypotenus
Sin y = s / 8
Opposite side = s ; hypotenus = 8
Tan y = opposite / Adjacent
Tan y = s / t
Adjacent side = t
Then ;
Cos y = Adjacent / hypotenus
Hence,
Cos y = t / 8
Answer:
the answer is :
cos y°= t / 8
Step-by-step explanation:
I promise! I got this right, and.....you are welcome.
To eliminate the y-terms and solve for x in the fewest steps, by which constants should the equations be multiplied by before adding the equations together?
First Equation: 5x − 4y = 28
Second equation: 3x - 9y = 30
The first equation should be multiplied by 3 and the second equation by 5.
The first equation should be multiplied by 3 and the second equation by −5.
The first equation should be multiplied by 9 and the second equation by 4.
The first equation should be multiplied by 9 and the second equation by −4
Answer:
The first equation should be multiplied by 9 and the second equation by −4
Step-by-step explanation:
Given the simultaneous equation
First Equation: 5x − 4y = 28
Second equation: 3x - 9y = 30
In order to eliminate y, we must make the coefficient of x in both expression to be equal.
To do that the first equation should be multiplied by 9 (negative value of the coefficient of y in equation 2)and the second equation by -4( (coefficient of y in equation 1)
Domain and range problem Help
Answer:
Range y≤-1
Domain all reals
Step-by-step explanation:
The range is the output values (y)
Y is less than or equal to -1
y≤-1
The domain is the values that the input can take
the arrows on the ends of the graph tells us x can take all real numbers
The range is the span of y-values. What is the smallest possible y-value and what is the largest possible y-value?
For this problem, the y-values start at -1 and decrease infinitely. Therefore, the range is y <= -1.
The domain is the span of x-values. What is the smallest possible x-value and what is the largest possible x-value?
For this problem, the parabola will keep expanding horizontally (or to the left and right). Therefore, the range is all real numbers.
Hope this helps!
Which number produces an irrational number when added to 0.4
Answer:
0.31311311131111....
Step-by-step explanation:
We need to tell a number which when adds to 0.4 makes it a Irrational Number . We know that ,
Rational number :- The number in the form of p/q where p and q are integers and q is not equal to zero is called a Rational number .
Irrational number :- Non terminating and non repeating decimals are called irrational number .
Recall the property that :-
Property :- Sum of a Rational Number and a Irrational number is Irrational .
So basically here we can add any Irrational number to 0.4 to make it Irrational . One Irrational number is ,
[tex] \rm\implies Irrational\ Number = 0.31311311131111... [/tex]
So when we add this to 0.4 , the result will be Irrational . That is ,
[tex] \rm\implies 0.4 + 0.31311311131111 ... = 0.731311311131111 .. [/tex]
2. Express the number 1750 as a product of prime factors of the form:
p * qr * s
9514 1404 393
Answer:
1750 = 2 · 5³ · 7
Step-by-step explanation:
It is often helpful to start with divisibility rules when finding prime factors of a small composite number.
The least-significant digit is even, so we know 2 is a factor.
1750/2 = 875
The least significant digit is 5, so we know 5 is a factor.
875/5 = 175
175/5 = 35
35/5 = 7
7 is a prime number, so we're done.
The factorization is ...
1750 = 2 · 5³ · 7
What percentage is
£7 of £20?
28kg of 40kg?
plz answer both questions
[tex]\huge❥︎\underbrace\mathfrak\red {SoLuTiOn}✈︎[/tex]
1)
[tex] £7 \: of \: £20 \\ \\ \fbox{considering as x} \\ \\ x\%of \: 20 = 7 \\ \\ x\% = \frac{7}{20} \times 100 \\ \\ x\% = \frac{7}{ \cancel{20}} \times \cancel{ 100} \\ \\ x\% = 7 \times 5 \\ \\ x\% = 35\%[/tex]
2)
[tex]28 \: kg \: of \: 40 \: kg \\ \\ \fbox{considering as x} \\ \\ x\% 40 = 28 \\ \\ x\% = \frac{28}{40} \times 100 \\ \\ x\% = \cancel \frac{28}{4 \cancel0} \times 10 \cancel0 \\ \\ x\% = 7 \times 10 \\ \\ x\% = 70\%[/tex]
Hope This Helps You ❤️According to the WHO MONICA Project the mean blood pressure for people in China is 128 mmHg with a standard deviation of 23 mmHg (Kuulasmaa, Hense & Tolonen, 1998). Assume that blood pressure is normally distributed.
a.) State the random variable.
b.) Find the probability that a person in China has blood pressure of 135 mmHg or more.
c.) Find the probability that a person in China has blood pressure of 141 mmHg or less.
d.) Find the probability that a person in China has blood pressure between 120 and 125 mmHg.
e.) Is it unusual for a person in China to have a blood pressure of 135 mmHg? Why or why not?
f.) What blood pressure do 90% of all people in China have less than?
Answer:
a) Mean blood pressure for people in China, which has mean 128 and standard deviation 23.
b) 0.3821 = 38.21% probability that a person in China has blood pressure of 135 mmHg or more.
c) 0.714 = 71.4% probability that a person in China has blood pressure of 141 mmHg or less.
d) 0.0851 = 8.51% probability that a person in China has blood pressure between 120 and 125 mmHg.
e) Since |Z| = 0.3 < 2, it is not unusual for a person in China to have a blood pressure of 135 mmHg.
f) 90% of all people in China have a blood pressure of less than 157.44 mmHg.
Step-by-step explanation:
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
The mean blood pressure for people in China is 128 mmHg with a standard deviation of 23 mmHg
This means that [tex]\mu = 128, \sigma = 23[/tex]
a.) State the random variable.
Mean blood pressure for people in China, which has mean 128 and standard deviation 23.
b.) Find the probability that a person in China has blood pressure of 135 mmHg or more.
This is 1 subtracted by the p-value of Z when X = 135, so:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{135 - 128}{23}[/tex]
[tex]Z = 0.3[/tex]
[tex]Z = 0.3[/tex] has a p-value of 0.6179.
1 - 0.6179 = 0.3821
0.3821 = 38.21% probability that a person in China has blood pressure of 135 mmHg or more.
c.) Find the probability that a person in China has blood pressure of 141 mmHg or less.
This is the p-value of Z when X = 141, so:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{141 - 128}{23}[/tex]
[tex]Z = 0.565[/tex]
[tex]Z = 0.565[/tex] has a p-value of 0.7140.
0.714 = 71.4% probability that a person in China has blood pressure of 141 mmHg or less.
d.) Find the probability that a person in China has blood pressure between 120 and 125 mmHg.
This is the p-value of Z when X = 125 subtracted by the p-value of Z when X = 120, so:
X = 125
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{125 - 128}{23}[/tex]
[tex]Z = -0.13[/tex]
[tex]Z = -0.13[/tex] has a p-value of 0.4483.
X = 120
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{120 - 128}{23}[/tex]
[tex]Z = -0.35[/tex]
[tex]Z = -0.35[/tex] has a p-value of 0.3632.
0.4483 - 0.3632 = 0.0851
0.0851 = 8.51% probability that a person in China has blood pressure between 120 and 125 mmHg.
e.) Is it unusual for a person in China to have a blood pressure of 135 mmHg? Why or why not?
From item b, when X = 135, Z = 0.3.
Since |Z| = 0.3 < 2, it is not unusual for a person in China to have a blood pressure of 135 mmHg.
f.) What blood pressure do 90% of all people in China have less than?
The 90th percentile, which is X when Z has a p-value of 0.9, so X when Z = 1.28.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]1.28 = \frac{X - 128}{23}[/tex]
[tex]X - 128 = 1.28*23[/tex]
[tex]X = 157.44[/tex]
90% of all people in China have a blood pressure of less than 157.44 mmHg.
6. 2(h-8)- h= h - 16
a.8
b. -8
c. infinitely many solutions
d. no solution
i need the answer and a explanation of how to get my answer i need soon pls hurry
Answer:
c. infinitely many solutions
General Formulas and Concepts:
Pre-Algebra
Distributive Properties
Equality Properties
Multiplication Property of Equality Division Property of Equality Addition Property of Equality Subtraction Property of EqualityAlgebra I
Terms/CoefficientsStep-by-step explanation:
Step 1: Define
Identify
2(h - 8) - h = h - 16
Step 2: Solve for h
[Distributive Property] Distribute 2: 2h - 16 - h = h - 16Combine like terms: h - 16 = h - 16[Addition Property of Equality] Add 16 on both sides: h = hHello from MrBillDoesMath!
Answer: c (infinitely many solutions)
Steps:
1) Simplify the original equation
2(h-8)- h= h - 16
2.As 2 (h-8) = 2h- 16, the equation in 1) is equivalent to
(2h-16) -h = h - 16
or
(2h-h) - 16 = h - 16
or
h - 16 = h -16
which is true for all values of h.
Regards, MrB
the angle between two lines is 60 degree. if the slope of one of them is 1. find the slope of other line
Answer:
-3.73
Step-by-step explanation:
solution:
Given:
Angle between two lines=60⁰
slope of first line=1
Or, tanA=1
Or, A= tan inverse (1)
so, A=45⁰
so, angle of inclination of first line=45⁰
Now,
angle of inclination of second line= A+ 60⁰
= 45⁰+60⁰
=105⁰
so, slope of second line = tan105.
= -3.73
Complete the input-output table:
x 3x + 7
0
4
8
14
Step-by-step explanation:
When x = 0,
3x + 7
= 3 ( 0 ) + 7
= 0 + 7
= 7
When x = 4,
3x + 7
= 3 ( 4 ) + 7
= 12 + 7
= 19
When x = 8,
3x + 7
= 3 ( 8 ) + 7
= 24 + 7
= 31
When x = 14,
3x + 14
= 3 ( 14 ) + 14
= 14 ( 3 + 1 )
= 14 ( 4 )
= 56
Select the correct answer.
A basketball team played 15 games and won 80% of them. If the team expects to play 30 games in by all, how many more games must it win to
finish the season with a 90% winning percentage?
A.12
B.14
C.15
D.27
a plane can fly 450 miles in the same time it takes a car to go 150 miles. if the car travels 100 mph slower than the plane, find the speed (in mph) of the plane
Answer:
The speed of the plane is 150 miles per hour, while the speed of the car is 50 miles per hour.
Step-by-step explanation:
Since a plane can fly 450 miles in the same time it takes a car to go 150 miles, if the car travels 100 mph slower than the plane, to find the speed (in mph) of the plane the following calculation must be performed:
450 to 150 is equal to 3: 1, that is, the plane travels three times the distance of the car.
Therefore, since 100/2 x 3 equals 150, the speed of the plane is 150 miles per hour, while the speed of the car is 50 miles per hour.
A certain species of virulent bacteria is being grown in a culture. It is observed that the rate of growth of the bacterial population is proportional to the number present. If there were 3000 bacteria in the initial polulation and the number doubled after the first 60 minutes, how many bacteria will be present after 2 hours
Answer:
12000 bacteria
Step-by-step explanation:
Recall that
60 minutes = 1 hour
Given that the rate of growth of the bacterial population is proportional to the number present.
If there were 3000 bacteria in the initial population and the number doubled after the first 60 minutes
Then after 60 minutes, the number of bacteria present would be
= 3000 * 2
= 6000
In another 60 minutes, the number would have doubled again, thus the number present then would be
= 6000 * 2
= 12000
Hence after 120 minutes, the number of bacteria present is 12000. 120 minutes is same as 2 hours
Russell is doing some research before buying his first house. He is looking at two different areas of the city, and he wants to know if there is a significant difference between the mean prices of homes in the two areas. For the 33 homes he samples in the first area, the mean home price is $168,300. Public records indicate that home prices in the first area have a population standard deviation of $37,825. For the 32 homes he samples in the second area, the mean home price is $181,900. Again, public records show that home prices in the second area have a population standard deviation of $25,070. Let Population 1 be homes in the first area and Population 2 be homes in the second area. Construct a 95% confidence interval for the true difference between the mean home prices in the two areas.
Answer:
The 95% confidence interval for the true difference between the mean home prices in the two areas is (-$29156.52, $1956.52).
Step-by-step explanation:
Before building the confidence interval, we need to understand the central limit theorem and subtraction of normal variables.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
First area:
33 homes, mean of $168,300, standard deviation of $37,825. Thus:
[tex]\mu_1 = 168300[/tex]
[tex]s_1 = \frac{37825}{\sqrt{33}} = 6584.5[/tex]
Second area:
33 homes, mean of $181,900, standard deviation of $25,070. Thus:
[tex]\mu_2 = 1819000[/tex]
[tex]s_2 = \frac{25070}{\sqrt{32}} = 4431.8[/tex]
Distribution of the difference:
[tex]\mu = \mu_1 - \mu_2 = 168300 - 181900 = -13600[/tex]
[tex]s = \sqrt{s_1^2+s_2^2} = \sqt{6584.5^2 + 4431.8^2} = 7937[/tex]
Confidence interval:
[tex]\mu \pm zs[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
95% confidence level
So [tex]\alpha = 0.05[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].
The lower bound of the interval is:
[tex]\mu - zs = -13600 - 1.96*7937 = -29156.52 [/tex]
The upper bound of the interval is:
[tex]\mu + zs = -13600 + 1.96*7937 = 1956.52[/tex]
The 95% confidence interval for the true difference between the mean home prices in the two areas is (-$29156.52, $1956.52).
Find the value of the variable y, where the sum of the fraction 2/y-3 and 6/y+3 is equal to the quotient.
PLEASE HELPPPPPPP NEED ASAPPPPPPP WILL GIVE BRAINLIEST TO FIRST CORRECT ANSWERRRRRR
Answer:
Here we need to solve:
[tex]\frac{2}{y - 3} + \frac{6}{y + 3 } = \frac{\frac{2}{y-3}}{\frac{6}{y + 3} }[/tex]
The sum of the fractions is equal to the quotient between the fractions.
Notice that the two values:
y = 3
y = -3
make the denominator equal to zero, so those values are restricted.
We can simplify the right side to get:
[tex]\frac{2}{y - 3} + \frac{6}{y + 3 } = \frac{\frac{2}{y-3}}{\frac{6}{y + 3} } = \frac{2*(y + 3)}{6*(y - 3)} = 3*\frac{y + 3}{y - 3}[/tex]
Now we can multiply both sides by (y - 3)
[tex](y - 3)*(\frac{2}{y - 3} + \frac{6}{y + 3 }) = 3*(y + 3)\\2 + 6*\frac{y -3}{y + 3} = 3*(y + 3)[/tex]
Now we can multiply both sides by (y + 3)
[tex](2 + 6*\frac{y -3}{y + 3})*(y + 3) = 3*(y + 3)*(y + 3)[/tex]
[tex]2*(y + 3) + 6*(y - 3) = 3*(y + 3)*(y + 3)\\\\2*y + 6 + 6*y - 18 = 3*(y^2 + 2*y*3 + 9)\\\\8*y - 12 = 3*y^2 + 6*y + 33\\\\0 = 3*y^2 + 6*y + 33 - 8*y + 12\\\\0 = 3*y^2 - 2*y + 45[/tex]
First, let's see the determinant of that quadratic equation:
[tex]D = (-2)^2 - 4*3*45 = -536[/tex]
We can see that it is negative, thus, there are no real solutions of the equation.
Thus, there is no value of y such that the origina equation is true,
Answer:
y=15
Step-by-step explanation:
PLEASE HELP
Identify the 15th term of the arithmetic sequence in which a. = 10 and ao = 20.
Answer:
The 15th term is 160
Step-by-step explanation:
The details are not clear. So, I will make the following assumptions
[tex]d = 10[/tex] ---- common difference
[tex]a_1 = 20[/tex] ---- first term
Required
The 15th term
This is calculated as:
[tex]a_{n} = a + (n - 1) * d[/tex]
Substitute 15 for n
[tex]a_{15} = a + (15 - 1) * d[/tex]
[tex]a_{15} = a + 14 * d[/tex]
Substitute values for d and a
[tex]a_{15} = 20 + 14 * 10[/tex]
[tex]a_{15} = 20 + 140[/tex]
[tex]a_{15} = 160[/tex]
SOMEONE HELP PLEASE ASAP PLES DONT LEAVE UR ANSWER AS AN IMAGE SOMETIMES I CANT SEE IMAGES. THANK YOU VERY MUCH! WILL MARK BRAINLIEST :)))
9514 1404 393
Answer:
x = -2/5 or -1
Step-by-step explanation:
The last two terms of the expression on the left can be factored also.
(5x+2)² +3(5x+2) = 0
And the common factor can be factored out:
(5x+2)(5x +2+3) = 0
5(5x +2)(x +1) = 0
Solutions to the equation make the factors zero:
5x +2 = 0 ⇒ x = -2/5
x +1 = 0 ⇒ x = -1
The values of x that are solutions to the equation are x = -2/5 and x = -1.
_____
Once you realize that (5x+2) is a factor, you know one solution is x = -2/5. The rest is just fluff to find the second solution. It is not required in order to answer the question.
A certain manufacturing process yields electrical fuses of which, in the long run
15% are defective. Find the probability that in a random sample of size n=10, fuses
selected from this process, there will be
(i) No defective fuse
(ii) At least one defective fuse
(iii) Exactly two defective fuses
(iv) At most one defective fuse
Answer:
i) 0.1969 = 19.69% probability that there will be no defective fuse.
ii) 0.8031 = 80.31% probability that there will be at least one defective fuse.
iii) 0.2759 = 27.59% probability that there will be exactly two defective fuses.
iv) 0.5443 = 54.43% probability that there will be at most one defective fuse.
Step-by-step explanation:
For each fuse, there are only two possible outcomes. Either it is defective, or it is not. The probability of a fuse being defective is independent of any other fuse, which means that the binomial probability distribution is used to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
And p is the probability of X happening.
15% are defective.
This means that [tex]p = 0.15[/tex]
We also have:
[tex]n = 10[/tex]
(i) No defective fuse
This is [tex]P(X = 0)[/tex]. So
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{10,0}.(0.15)^{0}.(0.85)^{10} = 0.1969[/tex]
0.1969 = 19.69% probability that there will be no defective fuse.
(ii) At least one defective fuse
[tex]P(X \geq 1) = 1 - P(X = 0)[/tex]
We already have P(X = 0) = 0.1969, so:
[tex]P(X \geq 1) = 1 - 0.1969 = 0.8031[/tex]
0.8031 = 80.31% probability that there will be at least one defective fuse.
(iii) Exactly two defective fuses
This is P(X = 2). So
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 2) = C_{10,2}.(0.15)^{2}.(0.85)^{8} = 0.2759[/tex]
0.2759 = 27.59% probability that there will be exactly two defective fuses.
(iv) At most one defective fuse
This is:
[tex]P(X \leq 1) = P(X = 0) + P(X = 1)[/tex]. So
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{10,0}.(0.15)^{0}.(0.85)^{10} = 0.1969[/tex]
[tex]P(X = 1) = C_{10,1}.(0.15)^{1}.(0.85)^{9} = 0.3474[/tex]
Then
[tex]P(X \leq 1) = P(X = 0) + P(X = 1) = 0.1969 + 0.3474 = 0.5443[/tex]
0.5443 = 54.43% probability that there will be at most one defective fuse.