Answer:
x=0,-3
Step-by-step explanation:
x(x+3)(x+3)=0
Using the zero product property
x=0 x+3=0 x+3 =0
x=0 x=-3 x=-3
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
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.
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.
Which equation represents the parabola with focus (8, 4) and vertex (8, 2)
Answer:
Step-by-step explanation:
The focus lies above the vertex, so the parabola opens upwards.
Why lines e and f must be parallel
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!
suppose two soccer teams consist of players with a combined average height of 66 inches. if team a has an average height of 68 inches and has twice as many members as team b, what is the average height of team b
Answer:
The average height of team b is 62 inches.
Step-by-step explanation:
Mean:
The mean of a data-set is the sum of all values in the data-set divided by the number of values, that is:
[tex]M = \frac{s}{n}[/tex]
Sum:
Team a: Mean of 68 inches, 2x members.
Team b: Mean of y inches, x members.
So
[tex]s = 68*2x + yx = x(136 + y)[/tex]
Number of athletes:
[tex]n = 2x + x = 3x[/tex]
What is the average height of team b?
[tex]66 = \frac{x(136+y)}{3x}[/tex]
[tex]66 = \frac{136 + y}{3}[/tex]
[tex]136 + y = 198[/tex]
[tex]y = 198 - 136 = 62[/tex]
The average height of team b is 62 inches.
Help 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
At Joe's Restaurant, 80 percent of the diners are new customers (N), while 20 percent are returning customers (R). Fifty percent of the new customers pay by credit card, compared with 70 percent of the regular customers. If a customer pays by credit card, what is the probability that the customer is a new customer?
Answer:
0.7407 = 74.07% probability that the customer is a new customer.
Step-by-step explanation:
Conditional Probability
We use the conditional probability formula to solve this question. It is
[tex]P(B|A) = \frac{P(A \cap B)}{P(A)}[/tex]
In which
P(B|A) is the probability of event B happening, given that A happened.
[tex]P(A \cap B)[/tex] is the probability of both A and B happening.
P(A) is the probability of A happening.
In this question:
Event A: Pays by credit card
Event B: New customer.
Probability of a customer paying by credit card:
50% of 80%(new customers).
70% of 20%(regular customers). So
[tex]P(A) = 0.5*0.8 + 0.7*0.2 = 0.54[/tex]
Probability of a customer paying by credit card and being a new customer:
50% of 80%, so:
[tex]P(A \cap B) = 0.5*0.8 = 0.4[/tex]
What is the probability that the customer is a new customer?
[tex]P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.4}{0.54} = 0.7407[/tex]
0.7407 = 74.07% probability that the customer is a new customer.
URGENT!!!!!! 15 POINTDS
Answer:
Option C
Step-by-step explanation:
thankful that there are graphing tools. see screenshot
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
The diameter of the circle is 2”. What is the area of the circle
Answer:
[tex]\pi[/tex]
Step-by-step explanation:
1. 2/2 =1 1 is the radius
2. [tex]A = \pi r^2[/tex]
3. [tex]A=\pi 1^2[/tex]
4. [tex]A=\pi[/tex]
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!
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.
If f(x) = x
2−3x+1
x−1
find f(-1) and f(-3)
Answer:
f(-1) = 2-3(-1) +1
= 7
f(-3)= 2-3(-3)+1
= 12
f(-1) = -1-1
= -2
f(-3) = -3-1
= -4
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
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
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]
find two factors of the first number such that their product is the first number and their sum is the second number.
70,17
9514 1404 393
Answer:
7, 10
Step-by-step explanation:
It often works well to look at the factor pairs that form the product.
70 = 1×70 = 2×35 = 5×14 = 7×10
The sums of these are 71, 37, 19, 17. The last pair of factors is the one of interest:
7 and 10.
3. line has undefined slope and passes through (1,8)
Answer: x = 1
Step-by-step explanation:
(any line with an undefined slope is a vertical line)
x = 1 has an undefined slope and passes through (1,8)
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
a.
What is 46.7% of
4/5?
Answer:
0.3736
Step-by-step explanation:
46.7 percent of [tex]\frac{4}{5}[/tex] is 0.3736.
What is the percentage?A percentage is a figure or ratio stated as a fraction of 100 in mathematics. Although the abbreviations "pct," "pct," and occasionally "pc" are also used, the percent sign, " percent ", is frequently used to signify it. A % is a number without dimensions and without a standard measurement.What is a fraction?A number is stated as a quotient in mathematics when the numerator and denominator are divided. Both are integers in a simple fraction. A fraction appears in the numerator or denominator of a complex fraction. The numerator of a proper fraction is less than the denominator.Solution -To find 46.7% of [tex]\frac{4}{5}[/tex].
So,
[tex]\frac{46.7}{100}[/tex] × [tex]\frac{4}{5}[/tex]
[tex]\frac{0.467}{100}[/tex] × [tex]\frac{4}{5}[/tex]
⇒ [tex]0.3736[/tex]
Therefore, 46.7% of [tex]\frac{4}{5}[/tex] is 0.3736.
Know more about percentages here:
https://brainly.com/question/24304697
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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.
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
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.
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
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.
What is the other dimension of the rectangular cross section that is perpendicular to the base (the face that is shaded) and passes through the midpoints of the 10 cm edges?
________ centimeters by 18 centimeters
PLZ PLZ HELP
A rectangular prism with length of 10 centimeters, width of 8 centimeters, and height of 18 centimeters.
A. 2
B. 8
C. 10
D. 18
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=54