Answers
Answer:
3
Step-by-step explanation:
z - 2x
--------
y
Let x = 3 y = -4 and z =-6
-6 - 2(3)
--------
-4
-6 -6
---------
-4
-12
-----
-4
3
Answer:
3
Step-by-step explanation:
To solve this, we need to plug in each of the numbers to the equation.
x = 3, y = - 4, z = - 6
[tex]\frac{z-2x}{y} = \frac{-6-2(3)}{-4}[/tex]
Let's solve the parenthesis first. - 2 * 3 = - 6.
[tex]\frac{-6-6}{-4}[/tex]
We then subtract -6 - 6.
[tex]\frac{-12}{-4}[/tex]
Then, we divide (cancel out the negatives).
[tex]-12 / -4 =3[/tex]
Our final answer is 3. Hope this helps!
Related Questions
2000 people attended a baseball game. 1300 of the people attending supported the home team, while 700 supported the visiting team. What percentage of people attending supported the home team?
Answers
Answer:
Percentage of home team supporters =65%
Percentage of visiting team supporters =35%
Step-by-step explanation:
Total attendees=2,000 people
Home team supporters=1,300
Visiting team supporters=700
What percentage of people attending supported the home team?
Percentage of people attending who supported the home team = home team supporters / total attendees × 100
=1,300/2,000 × 100
=0.65 × 100
=65%
Visiting team supporters = visiting team supporters / total attendees
× 100
=700/2000 × 100
=0.35 × 100
=35%
Alternatively,
Visiting team supporters = percentage of total attendees - percentage of home team supporters
=100% - 65%
=35%
Find the union and interesection of each of the following A={3,6,9,12}, B ={6,8,9}
Answers
Answer:
Hello,
The answer would be,
A union B = {3,6,9,12}
and A intersection B= {6,9}
Answer:
[tex]\huge\boxed{ A\ union \ B = \{3,6,8,9,12\}}[/tex]
[tex]\huge\boxed{A\ intersection \ B = \{6,9\}}[/tex]
Step-by-step explanation:
A = {3,6,9,12}
B = {6,8,9}
A∪B = {3,6,9,12} ∪ { 6,8,9} [Union means all of the elements should be included in the set of A∪B]
=> A∪B = {3,6,8,9,12}
Now,
A∩B = {3,6,9,12} ∩ {6,8,9} [Intersection means common elements of the set]
=> A∩B = {6,9}
Lori buys a $586 certificate of deposit (CD) that earns 6.6% interest that compounds monthly. How much will the CD be worth in 13 years? Express your answer rounded correctly to the nearest cent. Do not include units on your answer.
Answers
Answer:
$1344.9Step-by-step explanation:
This problem can be solved using the compound interest formula
[tex]A= P(1+r)^t[/tex]
Given data
A, final amount =?
P, principal = $586
rate, r= 6.6% = 0.066
Time, t= 13 years
Substituting our values into the expression we have
[tex]A= 586(1+0.066)^1^3\\\ A= 586*(1.066)^13\\\ A= 586*2.295\\\ A= 1344.87[/tex]
To the nearest cent the in 13 years the CD will be worth $1344.9
Help please!!! Thank you
Answers
Answer:
B: 54
Step-by-step explanation:
for the first digit: 1 or 3 (2 choices)
for the second digit: 0, 1, or 3 (3 choices)
for the third digit: 0, 1, or 3 (3 choices)
for the forth digit: 0, 1, or 3 (3 choices)
2×3×3×3=54
Answer:
B) 54
Step-by-step explanation:
There are 3 numbers, but in the fourth positon (tens of thousands) if i put the zero no give value, then, in this position only have 2 options:
2*3*3*3 = 54
Solve the equation using square roots x^2+20=4
Answers
Answer:
Step-by-step explanation:
x^2+20=4 first isolate the variable by subtracting 20 on both sides.
x^2=-16 again isolate the variable but this time you square root both sides.
[tex]\sqrt{x}^2[/tex]=[tex]\sqrt{-16[/tex] then simplify
x= ±4
What is the issue with the work? It is wrong. Please answer this for points!
Answers
Answer:
3 ( a ) : x = 3.6,
3 ( b ) : x = 5
Step-by-step explanation:
For 3a, we can calculate the value of x through Pythagorean Theorem, which seemingly was your approach. However, the right triangle with x present as the leg, did not have respective lengths 9.6 and 12. The right angle divides 9.6 into two congruent parts, making one of the legs of this right triangle 9.6 / 2 = 4.8. The hypotenuse will be 12 / 2 as well - as this hypotenuse is the radius, half of the diameter. Note that 12 / 2 = 6.
( 4.8 )² + x² = ( 6 )²,
23.04 + x² = 36,
x² = 36 - 23.04 = 12.96,
x = √12.96, x = 3.6
Now as you can see for part b, x is present as the radius. Length 3 forms a right angle with length 8, dividing 8 into two congruent parts, each of length 4. We can form a right triangle with the legs being 4 and 3, the hypotenuse the radius. Remember that all radii are congruent, and therefore x will be the value of this hypotenuse / radius.
( 4 )² + ( 3 )² = ( x )²,
16 + 9 = x² = 25,
x = √25, x = 5
Suppose x varies directly with the square root of y and inversely with the cube root of z. What equation models this combined variation?
Answers
Answer:
[tex]\huge\boxed{x = k \frac{\sqrt{y} }{\sqrt[3]{z} }}[/tex]
Step-by-step explanation:
Given that:
1) x ∝ √y
2) x ∝ [tex]\frac{1}{\sqrt[3]{z} }[/tex]
Combining the proportionality
=> x ∝ [tex]\frac{\sqrt{y} }{\sqrt[3]{z} }[/tex]
=> [tex]x = k \frac{\sqrt{y} }{\sqrt[3]{z} }[/tex]
Where k is the constant of proportionality.
Ajar contains 4 red marbles numbered 1 to 4 and 10 blue marbles numbered 1 to 10. A marble is
drawn at random from the jar. Find the probability of the given event.
(a) The marble is red
Your answer is:
(b) The marble is odd-numbered
Your answer is:
(C) The marble is red or odd-numbered
Your answer is:
(d) The marble is blue or even-numbered
Your answer is:
Question Help M Message instructor
Answers
Answer:
a)2/7
b)1/2
c)9/14
d)6/7
Step-by-step explanation:
The jar contains 4 red marbles, numbered 1 to 4 which means
Red marbles = (R1) , (R2) , (R3) , (R4)
It also contains 10 blue marbles numbered 1 to 10 which means
Blue marbles = (B1) , (B2) , (B3) , (B4) , (B5) , (B6) , (B7) , (B8) , (B9) , (B10) .
We can calculate total marbles = 4red +10 blues
=14marbled
Therefore, total marbles= 14
The marbles that has even number = (R2) , (R4) ,(B2) , (B4) , (B6) , (B8) , (B10) =7
Total number of Blue marbles = 10
Blue and even marbles = 5
(a) The marble is red
P(The marble is red)=total number of red marbles/Total number of marbles
=4/14
=2/7
(b) The marble is odd-numbered
Blue marbles with odd number= (B1) , (B3) , (B5) , (B7) , (B9) ,
Red marbles with odd number = (R1) , (R3)
Number of odd numbered =(5+2)=7
P(marble is odd-numbered )= Number of odd numbered/ Total number of marbles
P(marble is odd-numbered )=7/14
=1/2
(C) The marble is red or odd-numbered?
Total number of red marbles = 14
Number of red and odd marbles = 2
The marbles that has odd number = (R1) , (R3) ,(B1) , (B3) , (B5) , (B7) , (B9) =7
n(red or even )= n(red) + n(odd)- n(red and odd)
=4+7-2
=9
P(red or odd numbered)= (number of red or odd)/(total number of the marble)
= 9/14
(d) The marble is blue or even-numbered?
Number of Blue and even marbles = 5
Total number of Blue marbles = 10
Number of blue that are even= 5
The marbles that has even number = (R2) , (R4) ,(B2) , (B4) , (B6) , (B8) , (B10)
=7
n(Blue or even )= n(Blue) + n(even)- n(Blue and even)
= 10+7-5 =12
Now , the probability the marble is blue or even numbered can be calculated as
P(blue or even numbered)= (number of Blue or even)/(total number of the marble)
= 12/14
= 6/7
This test statistic leads to a decision to...
reject the null
accept the null
fail to reject the null
As such, the final conclusion is that...
There is sufficient evidence to warrant rejection of the claim that the population mean is not equal to 88.9.
There is not sufficient evidence to warrant rejection of the claim that the population mean is not equal to 88.9.
The sample data support the claim that the population mean is not equal to 88.9.
There is not sufficient sample evidence to support the claim that the population mean is not equal to 88.9.
Answers
Answer:
There is not sufficient sample evidence to support the claim that the population mean is not equal to 88.9.
Step-by-step explanation:
We are given the following hypothesis below;
Let [tex]\mu[/tex] = population mean.
So, Null Hypothesis, [tex]H_0[/tex] : [tex]\mu[/tex] = 88.9 {means that the population mean is equal to 88.9}
Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu\neq[/tex] 88.9 {means that the population mean is different from 88.9}
The test statistics that will be used here is One-sample t-test statistics because we don't know about population standard deviation;
T.S. = [tex]\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }[/tex] ~ [tex]t_n_-_1[/tex]
where, [tex]\bar X[/tex] = sample mean = 81.3
s = sample standard deviation = 13.4
n = sample size = 7
So, the test statistics = [tex]\frac{81.3-88.9}{\frac{13.4}{\sqrt{7} } }[/tex] ~ [tex]t_6[/tex]
= -1.501
The value of t-test statistics is -1.501.
Also, the P-value of the test statistics is given by;
P-value = P([tex]t_6[/tex] < -1.501) = 0.094
Since the P-value of our test statistics is more than the level of significance as 0.094 > 0.01, so we have insufficient evidence to reject our null hypothesis as the test statistics will not fall in the rejection region.
Therefore, we conclude that the population mean is equal to 88.9.
If a person earns $8.74 per hour, estimate how much the person would earn per year. Assume a person works 40 hours per week and 50 weeks per year.
Answers
Answer:
$17,480 per year.
Step-by-step explanation:
Amount earned per hour = $8.74
If a person works for 40 hours every week for 50 weeks in a year, number of hours worked in a year = [tex] 40hrs*50weeks = 2000 hrs [/tex]
Estimated amount earned per year by the person = [tex] 2000hrs * 8.74 dollars [/tex]
= $17,480 per year.
Which table represents a linear function?
x y
1 5
2 10
3 15
4 20
5 25
x y
1 5
2 20
3 45
4 80
5 125
x y
1 5
2 25
3 125
4 625
5 3125
x y
1 2
2 4
3 7
4 16
5 32
Answers
Answer:
The first table on the list:
x 1 2 3 4 5
y 5 10 15 20 25
Step-by-step explanation:
A linear equation is when the slope is the exact same between each point. The way we find slope is by finding the change in "y" over the change in "x".
x-values: 1, 2/y-values: 5, 10---[tex]\frac{10-5}{2-1}[/tex]=5/1=5
x-values: 2, 3/y-values: 10, 15---[tex]\frac{15-10}{3-2}[/tex]=5/1=5
x-values: 3, 4/y-vaues: 15, 20---[tex]\frac{20-15}{4-3}[/tex]=5/1=5
x-values: 4, 5/y-values: 20, 25---[tex]\frac{25-20}{5-4}[/tex]=5/1=5
The slope for each change in points is 5, which means that this table represents a linear function.
The only table that represents a linear function is; Table 1
Linear functionA linear function is one that has the same slope for every coordinate point.
Looking at the tables, the one with same slope for all points is table 1 and we will prove that as follows;
At x = 1, y = 5 and;Slope = 5/1 = 5
At x = 2; y = 10 and;Slope = 10/2 = 5
At x = 3, y = 15 and;Slope = 15/3 = 5
At x = 4, y = 20 and;Slope = 20/4 = 5
At x = 5, y = 25 and;slope = 25/5 = 5
In conclusion, only table 1 represents a linear function.
Read more about Linear function at; https://brainly.com/question/15602982
Reducing scrap of 4-foot planks of hardwood is an important factor in reducing cost at a wood-floor manufacturing company. Accordingly, engineers at Lumberworks are investigating a potential new cutting method involving lateral sawing that may reduce the scrap rate. To examine its viability, two independent, random, representative samples of planks were examined. One sample contained 200 planks which were sawed using the old method. The other sample contained 400 planks which were sawed using the new method. Sixty-two of the 200 planks were scrapped under the old method of sawing, whereas 36 of the 400 planks were scrapped under the new method.
Required:
a. Construct the 90% confidence interval for the difference between the population scrap rates between the old and new methods, respectively.
b. Write the null and alternative hypotheses to test for differences in the population scrap rates between the old and new cutting methods, respectively.
c. Using the part a results, can we conclude at the 10% significance level that the scrap rate of the new method is different than the old method?
Answers
Answer:
The critical value for two tailed test at alpha=0.1 is ± 1.645
The calculated z= 9.406
Step-by-step explanation:
Formulate the hypotheses as
H0: p1= p2 there is no difference between the population scrap rates between the old and new cutting methods
Ha : p1≠ p2
Choose the significance level ∝= 0.1
The critical value for two tailed test at alpha=0.1 is ± 1.645
The test statistic is
Z = [tex]\frac{p_1- p_2}\sqrt pq(\frac{1}{n_1} + \frac{1}{n_2})[/tex]
p1= scrap rate of old method = 62/200=0.31
p2= scrap rate of new method = 36/400= 0.09
p = an estimate of the common scrap rate on the assumption that the two rates are same.
p = n1p1+ n2p2/ n1 + n2
p =200 (0.31) + 400 (0.09) / 600
p= 62+ 36/600= 98/600 =0.1633
now q = 1-p= 1- 0.1633= 0.8367
Thus
z= 0.31- 0.09/ √0.1633*0.8367( 1/200 + 1/400)
z= 0.301/√ 0.13663( 3/400)
z= 0.301/0.0320
z= 9.406
The calculated value of z falls in the critical region therefore we reject the null hypothesis and conclude that the 10% significance level that the scrap rate of the new method is different from the old method.
How to convert 2cm to feet?
Answers
Answer:
Divide by 30.48: It would be 0.0656168 feet.
Step-by-step explanation:
Answer:
0.0656
Step-by-step explanation:
2.54 cm = 1 in
12 in = 1 ft
2.54 * 12 = 30.48
2/30.48 = 0.0656167979
Which expression is equivalent to 2(5)^4
Answers
Answer:
2·5·5·5·5
Step-by-step explanation:
2(5)^4 is equivalent to 2·5·5·5·5; 2 is used as a multiplicand just once, but 5 is used four times.
Ben and Cam are scuba diving. Ben is 15.8 meters below the
surface of the water. Cam is 4.2 meters above Ben. What is Cam's
position relative to the surface of the water?
Answers
=======================================================
Explanation:
Check out the diagram below.
Draw a vertical number line with 0 at the center. The positive values are above it, while the negative values are below it.
Between -15 and -16, closer to -16, plot the value -15.8 to indicate Ben's position. I have done so as the point B.
We move 4.2 units up to arrive at Cam's position
-15.8 + 4.2 = -11.6
So Cam is 11.6 meters below the surface of the water.
Help Me With This
show work
Answers
Answer:
1. Make a list of activities and the number of students:
Watching TV: 32
Talking on the phone: 41
Video games: 24
Reading: 15
2. Then combine the data in a bar graph as shown in the picture
What is the area, in square meters, of the shaded part of the rectangle shown below?
Answers
Answer:
C) 100 cm²
Step-by-step explanation:
(14*6)/2*10
20/2*10
10*10
100
The area of the given shaded part of the rectangle is 100 square meters as shown.
What is the area of a triangle?The entire space filled by a triangle's three sides in a two-dimensional plane is defined as its area.
The fundamental formula for calculating the area of a triangle is A = 1/2 b h.
The area of the shaded part = area of the rectangle - area of the triangle
The area of the shaded part = 14 × 10 - (1/2) × 8 × 10
The area of the shaded part = 140 - 80/2
The area of the shaded part = 140 - 40
Apply the subtraction operation, and we get
The area of the shaded part = 100 meters²
Thus, the area of the given shaded part of the rectangle is 100 square meters.
Learn more about the triangles here:
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Find y using the Angle Sum Theorem
Answers
Step-by-step explanation:
Hey, there!!
Look this figure, simply we find that;
In triangle ABC,
angle CBD is an exterior angle of a triangle.
and its measure is 90°
Then,
angle CBD= y +48° {sum of interior opposite angle is equal to exterior angle or from theorem}.
or, 90°= y + 48°
Shifting, 48° in left side,
90°-48°= y
Therefore, the value of y is 42°.
Hope it helps...
What is the value of (–7 + 3i) + (2 – 6i)?
a. –9 – 3i
b. –9 + 9i
c. –5 + 9i
d. –5 – 3i
Answers
Answer:
d
Step-by-step explanation:
(-7 + 3i) + (2-6i)
=-7 + 3i + 2 -6i
=(-7+2) + (3i -6i)
=-5 -3i
Answer:
(-7+3I)+(2-6I)
= -7+3i+2-6i
= -5-3I
so answer is d ie -5-3i
A bag contains 12 blue marbles, 5 red marbles, and 3 green marbles. Jonas selects a marble and then returns it to the bag before selecting a marble again. If Jonas selects a blue marble 4 out of 20 times, what is the experimental probability that the next marble he selects will be blue? A. .02% B. 2% C. 20% D. 200% Please show ALL work! <3
Answers
Answer:
20 %
Step-by-step explanation:
The experimental probability is 4/20 = 1/5 = .2 = 20 %
Evaluate 3h(2) + 2k(3) =
Answers
Answer:
6h + 6kStep-by-step explanation:
[tex]3h\left(2\right)+2k\left(3\right)\\\\\mathrm{Remove\:parentheses}:\quad \left(a\right)=a\\\\=3h\times \:2+2k\times \:3\\\\\mathrm{Multiply\:the\:numbers:}\:3\times \:2=6\\\\=6h+2\times \:3k\\\\\mathrm{Multiply\:the\:numbers:}\:2\times \:3=6\\\\=6h+6k[/tex]
Answer:
Answers for E-dge-nuityyy
Step-by-step explanation:
(h + k)(2) = 5
(h – k)(3) = 9
Evaluate 3h(2) + 2k(3) = 17
For this problem, use the tables and charts shown in this section. (Use picture provided)
A United States Citizen returning to the States declares the following items at the customs office:
3 shirts at $8.50 each
2 dresses at $27.50 each
1 pair of gold cuff links at $17.50 per pair
If he has not used his duty free exemption yet, how much duty should he pay?
0 $0.00
$5.00
$10.00
$300
Answers
Answer:
0
Step-by-step explanation:
0 because there is a $100 duty free exemption.
answer:
For this problem, use the tables and charts shown in this section.
A United States Citizen returning to the States declares the following items at the customs office:
3 shirts at $8.50 each
2 dresses at $27.50 each
1 pair of gold cuff links at $17.50 per pair
If he has not used his duty free exemption yet, how much duty should he pay?
$0.00 !
$5.00
$10.00
$300
Solve for x (x+4)/3 = 2.
a. x = -2
b. x=2
c. x = 2/3
d. x= -10/3
Answers
Answer:
The answer is option BStep-by-step explanation:
[tex] \frac{x + 4}{3} = 2[/tex]
To solve it first of all cross multiply
That's
x + 4 = 6
Move 4 to the right side of the equation
The sign changes to negative
That's
x = 6 - 4
We have the final answer as
x = 2Hope this helps you
Can someone help? This hard
Answers
Answer:
The expression = [tex] \frac{40}{y - 16} [/tex]
Value of the expression = 4 (when y is 20)
Step-by-step explanation:
Quotient simply means the result you get when you divide two numbers. Thus, dividend (the numerator) ÷ divisor (the denominator) = quotient.
From the information given to us here,
the dividend = 40
the divisor = y - 16
The quotient = [tex] \frac{40}{y - 16} [/tex]
There, the expression would be [tex] \frac{40}{y - 16} [/tex]
Find the value of the expression when y = 20.
Plug in 20 for y in the expression and evaluate.
[tex] \frac{40}{y - 16} [/tex]
[tex] = \frac{40}{20 - 16} [/tex]
[tex] = \frac{40}{4} = 10 [/tex]
The value of the expression, when y is 20, is 4.
A box contain 12 balls in which 4 are white 3 are blue and 5 are red.3 balls are drawn at random from the box.find the chance that all three are selected
Answers
Answer:
3/11
Step-by-step explanation:
In the above question, we have the following information
Total number of balls = 12
White balls = 4
Blue balls = 3
Red balls = 5
We are to find the chance of probability that if we select 3 balls, all the three are selected.
Hence,
Probability ( all the three balls are selected) = P(White ball) × P(Blue ball) × P( Red ball)
Probability ( all the three balls are selected) = 4/12 × 3/11 × 5/10
= 60/1320
= 1/22
The number of ways by which we can selected all the three balls is a total of 6 ways:
WBR = White, Blue, Red
WRB = White, Red, Blue
RBW = Red, Blue, White
RWB = Red, White, Blue
BRW = Blue, Red, White
BWR = Blue, White, Red
Therefore, the chance that all three are selected :
1/22 × 6 ways = 6/22 = 3/11
When csc(Theta)sin(Theta) is simplified, what is the result? StartFraction 1 Over cosecant squared EndFraction StartFraction 1 Over sine squared EndFraction 0 1
Answers
Step-by-step explanation:
csc θ sin θ
(1 / sin θ) sin θ
1
The simplified value of the given expression comes to be 1.
The given expression is:
[tex]cosec\theta.sin\theta[/tex]
What is the trigonometric ratio [tex]cosec\theta[/tex]?The trigonometric ratio [tex]cosec\theta[/tex] is the ratio of the hypotenuse to the opposite side. It is the inverse of [tex]sin\theta[/tex].
[tex]cosec\theta=\frac{1}{sin\theta}[/tex]
We know that [tex]cosec\theta=\frac{1}{sin\theta}[/tex]
So [tex]cosec\theta.sin\theta[/tex]
[tex]=\frac{1}{sin\theta} .sin\theta[/tex]
=1
So, the simplified value is 1.
Hence, the simplified value of the given expression comes to be 1.
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Assume that females have pulse rates that are normally distributed with a mean of μ=73.0 beats per minute and a standard deviation of σ=12.5 beats per minute. Complete parts (a) through (c) below.a. If 1 adult female is randomly selected, find the probability that her pulse rate is less than 76 beats per minute.b. If 25 adult females are randomly selected, find the probability that they have pulse rates with a mean less than 76 beats per minute.c. Why can the normal distribution be used in part (b), even though the sample size does not exceed 30?A. Since the mean pulse rate exceeds 30, the distribution of sample means is a normal distribution for any sample size.B. Since the distribution is of individuals, not sample means, the distribution is a normal distribution for any sample size.C. Since the distribution is of sample means, not individuals, the distribution is a normal distribution for any sample size.D. Since the original population has a normal distribution, the distribution of sample means is a normal distribution for any sample size.
Answers
Answer:
a. the probability that her pulse rate is less than 76 beats per minute is 0.5948
b. If 25 adult females are randomly selected, the probability that they have pulse rates with a mean less than 76 beats per minute is 0.8849
c. D. Since the original population has a normal distribution, the distribution of sample means is a normal distribution for any sample size.
Step-by-step explanation:
Given that:
Mean μ =73.0
Standard deviation σ =12.5
a. If 1 adult female is randomly selected, find the probability that her pulse rate is less than 76 beats per minute.
Let X represent the random variable that is normally distributed with a mean of 73.0 beats per minute and a standard deviation of 12.5 beats per minute.
Then : X [tex]\sim[/tex] N ( μ = 73.0 , σ = 12.5)
The probability that her pulse rate is less than 76 beats per minute can be computed as:
[tex]P(X < 76) = P(\dfrac{X-\mu}{\sigma}< \dfrac{X-\mu}{\sigma})[/tex]
[tex]P(X < 76) = P(\dfrac{76-\mu}{\sigma}< \dfrac{76-73}{12.5})[/tex]
[tex]P(X < 76) = P(Z< \dfrac{3}{12.5})[/tex]
[tex]P(X < 76) = P(Z< 0.24)[/tex]
From the standard normal distribution tables,
[tex]P(X < 76) = 0.5948[/tex]
Therefore , the probability that her pulse rate is less than 76 beats per minute is 0.5948
b. If 25 adult females are randomly selected, find the probability that they have pulse rates with a mean less than 76 beats per minute.
now; we have a sample size n = 25
The probability can now be calculated as follows:
[tex]P(\overline X < 76) = P(\dfrac{\overline X-\mu}{\dfrac{\sigma}{\sqrt{n}}}< \dfrac{ \overline X-\mu}{\dfrac{\sigma}{\sqrt{n}}})[/tex]
[tex]P( \overline X < 76) = P(\dfrac{76-\mu}{\dfrac{\sigma}{\sqrt{n}}}< \dfrac{76-73}{\dfrac{12.5}{\sqrt{25}}})[/tex]
[tex]P( \overline X < 76) = P(Z< \dfrac{3}{\dfrac{12.5}{5}})[/tex]
[tex]P( \overline X < 76) = P(Z< 1.2)[/tex]
From the standard normal distribution tables,
[tex]P(\overline X < 76) = 0.8849[/tex]
c. Why can the normal distribution be used in part (b), even though the sample size does not exceed 30?
In order to determine the probability in part (b); the normal distribution is perfect to be used here even when the sample size does not exceed 30.
Therefore option D is correct.
Since the original population has a normal distribution, the distribution of sample means is a normal distribution for any sample size.
In a local university, 10% of the students live in the dormitories. A random sample of 100 students is selected for a particular study. Carry answer to the nearest ten-thousandths. (Bonus Question)
a. What is the probability that the sample proportion (the proportion living in the dormitories) is between 0.172 and 0.178?
b. What is the probability that the sample proportion (the proportion living in the dormitories) is greater than 0.025?
Answers
Answer:
a
[tex]P( 0.172 < X < 0.178 ) = 0.00354[/tex]
b
[tex]P( X >0.025 ) = 0.99379[/tex]
Step-by-step explanation:
From the question we are told that
The population proportion is [tex]p = 0.10[/tex]
The sample size is [tex]n = 100[/tex]
Generally the standard error is mathematically represented as
[tex]SE = \sqrt{\frac{ p (1 - p )}{n} }[/tex]
=> [tex]SE = \sqrt{\frac{ 0.10 (1 - 0.10 )}{100} }[/tex]
=> [tex]SE =0.03[/tex]
The sample proportion (the proportion living in the dormitories) is between 0.172 and 0.178
[tex]P( 0.172 < X < 0.178 ) = P (\frac{ 0.172 - 0.10}{0.03} < \frac{ X - 0.10}{SE} < \frac{ 0.178 - 0.10}{0.03} )[/tex]
Generally [tex]\frac{ X - 0.10}{SE} = Z (The \ standardized \ value \ of X )[/tex]
[tex]P( 0.172 < X < 0.178 ) = P (\frac{ 0.172 - 0.10}{0.03} <Z < \frac{ 0.178 - 0.10}{0.03} )[/tex]
[tex]P( 0.172 < X < 0.178 ) = P (2.4 <Z < 2.6 )[/tex]
[tex]P( 0.172 < X < 0.178 ) = P(Z < 2.6 ) - P (Z < 2.4 )[/tex]
From the z-table
[tex]P(Z < 2.6 ) = 0.99534[/tex]
[tex]P(Z < 2.4 ) = 0.9918[/tex]
[tex]P( 0.172 < X < 0.178 ) =0.99534 - 0.9918[/tex]
[tex]P( 0.172 < X < 0.178 ) = 0.00354[/tex]
the probability that the sample proportion (the proportion living in the dormitories) is greater than 0.025 is mathematically evaluated as
[tex]P( X >0.025 ) = P (\frac{ X - 0.10}{SE} > \frac{ 0.0025- 0.10}{0.03} )[/tex]
[tex]P( X >0.025 ) = P (Z > -2.5 )[/tex]
From the z-table
[tex]P (Z > -2.5 ) = 0.99379[/tex]
Thus
[tex]P( X >0.025 ) = P (Z > -2.5 ) = 0.99379[/tex]
if y = 2√x÷ 1–x', show that dy÷dx = x+1 ÷ √x(1–x)²
Answers
Answer: see proof below
Step-by-step explanation:
Use the Quotient rule for derivatives:
[tex]\text{If}\ y=\dfrac{a}{b}\quad \text{then}\ y'=\dfrac{a'b-ab'}{b^2}[/tex]
Given: [tex]y=\dfrac{2\sqrtx}{1-x}[/tex]
[tex]\sqrtx[/tex][tex]a=2\sqrt x\qquad \rightarrow \qquad a'=\dfrac{1}{\sqrt x}\\\\b=1-x\qquad \rightarrow \qquad b'=-1[/tex]
[tex]y'=\dfrac{\dfrac{1-x}{\sqrt x}-(-2\sqrt x)}{(1-x)^2}\\\\\\.\quad =\dfrac{\dfrac{1-x}{\sqrt x}-(-2\sqrt x)\bigg(\dfrac{\sqrt x}{\sqrt x}\bigg)}{(1-x)^2}\\\\\\.\quad =\dfrac{1-x+2x}{\sqrt x(1-x)^2}\\\\\\.\quad =\dfrac{x+1}{\sqrt x(1-x)^2}[/tex]
LHS = RHS: [tex]\dfrac{x+1}{\sqrt x(1-x)^2}=\dfrac{x+1}{\sqrt x(1-x)^2}\qquad \checkmark[/tex]
While walking from the car into your dormitory you dropped your engagement ring somewhere in the snow. The path is 30 feet long. You are distraught because the density of its location seems to be constant along this 30-foot route. a) What is the probability that the ring is within 12 feet of your car
Answers
Answer:
0.4
Step-by-step explanation:
we are required to find the probability that the ring is within 12 meters from nthe car.
we start by defining a random variable x to be the distance from the car. the car is the starting point.
x follows a normal distribution (0,30)
[tex]f(x)=\frac{1}{30}[/tex]
[tex]0<x<30[/tex]
probabilty of x ≤ 12
= [tex]\int\limits^a_ b{\frac{1}{30} } \, dx[/tex]
a = 12
b = 0
[tex]\frac{1}{30} *(12-0)[/tex]
[tex]\frac{12}{30} = 0.4[/tex]
therefore 0.4 is the probability that the ring is within 12 feet of your car.
