You are given the sample mean and the population standard deviation. Use this information to construct the​ 90% and​ 95% confidence intervals for the population mean. Interpret the results and compare the widths of the confidence intervals.

From a random sample of 74 ​dates, the mean record high daily temperature in a certain city has a mean of 85.22 degrees F. Assume the population standard deviation is 13.97 degrees F.

Answers

Answer 1

Answer:

Very confused! at 95% confidence level, the true population mean will be between 134.33 and 145.67.

Step-by-step explanation:

A random sample of 45 home theater systems has a mean price of ​$140.00

Assume the population standard deviation is ​$19.40

population standard deviation is 19.40

sample size is 45.

standard error of the sample mean is 19.40 / sqrt(45) = 2.89198

at 90% confidence level, critical z is plus or minus 1.645.

at 95% confidence level, critical z is plus or minus 1.96.

critical raw score will be sample mean plus or minus critical z-score * standard error of the mean.

your sample mean is 140.

your standard error of the mean is 2.89198

at 90% confidence level, your critical raw score will be 140 plus or minus 1.645 * 2.89198.

that becomes 140 plus or minus 4.76 rounded to the nearest penny.

at 90% confidence level, the true population mean will be between 135.24 and 144.76.

at 95% confidence level, your critical raw score will be 140 plus or minus 1.96 * 2.89198.

that becomes 140 plus or minus 5.67 rounded to the nearest penny.

Answer 2

Using the z-distribution, it is found that:

The 90% confidence interval for the population mean is (82.55, 87.89). It means that we are 90% sure that the true population mean is between these two values.The 95% confidence interval for the population mean is (82.04, 88.40). It means that we are 95% sure that the true population mean is between these two values.The higher the confidence level, the higher the critical value is, and thus, a higher confidence level leads to a wider interval.

We are given the standard deviation for the population, and thus, the z-distribution is used.

The information is:

Sample mean of [tex]\overline{x} = 85.22[/tex].Population standard deviation of [tex]\sigma = 13.97[/tex].Sample size of 74, thus [tex]n = 74[/tex].

A z-confidence interval is given by:

[tex]\overline{x} \pm z\frac{\sigma}{\sqrt{n}}[/tex]

We have to find the critical value, which is z with a p-value of [tex]\frac{1 + \alpha}{2}[/tex], in which [tex]\alpha[/tex] is the confidence level.

For the 90% confidence interval, [tex]\alpha = 0.9[/tex], thus, z with a p-value of [tex]\frac{1 + 0.9}{2} = 0.95[/tex], which means that it is z = 1.645.

Then, the 90% confidence interval is:

[tex]\overline{x} - z\frac{\sigma}{\sqrt{n}} = 85.22 - 1.645\frac{13.97}{\sqrt{74}} = 82.55[/tex]

[tex]\overline{x} + z\frac{\sigma}{\sqrt{n}} = 85.22 + 1.645\frac{13.97}{\sqrt{74}} = 87.89[/tex]

The 90% confidence interval for the population mean is (82.55, 87.89). It means that we are 90% sure that the true population mean is between these two values.

For the 95% confidence interval, [tex]\alpha = 0.95[/tex], thus, z with a p-value of [tex]\frac{1 + 0.95}{2} = 0.975[/tex], which means that it is z = 1.96.

Then, the 95% confidence interval is:

[tex]\overline{x} - z\frac{\sigma}{\sqrt{n}} = 85.22 - 1.96\frac{13.97}{\sqrt{74}} = 82.04[/tex]

[tex]\overline{x} + z\frac{\sigma}{\sqrt{n}} = 85.22 + 1.96\frac{13.97}{\sqrt{74}} = 88.40[/tex]

The 95% confidence interval for the population mean is (82.04, 88.40). It means that we are 95% sure that the true population mean is between these two values.

The higher the confidence level, the higher the critical value is, and thus, a higher confidence level leads to a wider interval.

A similar problem is given at https://brainly.com/question/22596713


Related Questions

Casey has 8 1/2 yards of fabric she uses 2 1/2 yards to make a pillow and 3 yards to make curtains how much fabric is remaining

Answers

Answer:

3 yards

Step-by-step explanation:

8 1/2 - 2 1/2 = 6

6 - 3 = 3

Your answer is 3.

Please mark as brainliest.

Find the distance between the two numbers on a number line. Write your answer as a decimal.
-1.85 , 7.36

Answers

Answer:

9.21

Step-by-step explanation:

I'm pretty sure you just add the two numbers as positive numbers :/

The required distance on the number line between the points -1.85 and 7.36 is 9.21.

Given that,
To determine the distance between the two numbers on a number line points are -1.85 and 7.36.

What is a number line?

A number line is defined as the number marked on the line calibrated into an equal number of units. For example -1, 0, 1, and so on.

Here,
On the number line, -1.85 lies on the left of the zero, and 7.36 lies on the right so the required distance would be the addition of the two points. So,
Distance = 7.36 - (-1.85)
Distance = 7.36 + 1.86
Distance = 9.21

Thus, the required distance on the number line between the points -1.85 and 7.36 is 9.21.

Learn more about number line here:

brainly.com/question/17683084

#SPJ5

What is the slope-intercept form of the equation of the line that passes through the point (–6, 1) and is perpendicular to the graph of 2x + 3y = –5?

Answers

Divided by 5 is answer

Help me?? Anyone I'll vote brainliest and everything 5 stars!! :)

Answers

Answer: y - 3 = -1/5(x+5)

Step-by-step explanation:

Hope this helps

If m angle p is three less than twice the measure of angle q and angle p and angle q are supplementary angles. Find each angle measure

Answers

Answer:

m<P= 119

m<Q= 61

Step-by-step explanation:

3+(-h)+(-4)where h = -7.

Answers

Answer:

6

Step-by-step explanation:

3+(-h)+(-4)

Let h = -7

3+(- -7)+(-4)

3+(7)+(-4)

10 -4

6

Expand the expression
3(x-6)​

Answers

Answer:

3x-3(6) = 3x-18

Step-by-step explanation:

Hi :)

Use the distributive property to multiply 3 by x−6

= 3x−18

Hope this helps!

:)

Currently bank customers wait approximately 7.5 minutes during peak hours to be served by a teller. Suppose the bank manager hires another teller and wants to show that the wait time has now decreased. She takes a random sample of 50 customers during peak time and finds that the average wait time is 9.3 minutes. Which of the following statements is the correct alternative hypothesis?a) H1: µ < 7.5b) H1: µ ≠ 7.5c) H1: µ > 7.5d) H1: µ > 9.3e) H1: µ < 9.3

Answers

Answer:

a) H1: µ < 7.5

Step-by-step explanation:

From the given information:

mean = 7.5

sample size = 50

sample mean = 9.3

The main task we are to carry out is to identify the correct alternative hypothesis:

Now to do that, let's state the null and the alternative hypothesis from the given study.

The null hypothesis can be computed as:

[tex]\mathbf{H_o: \mu \geq 7.5}[/tex]

The alternative hypothesis can be computed as:

[tex]\mathbf{H_1: \mu < 7.5}[/tex]

Thus, this test hypothesis is a one-tailed test (left tailed).

Super easy math question pls help

Answers

Answer:

Thanks

Step-by-step explanation

6(9)+6(7)

also, 18(3)+14(3)

i rly have no idea what this one is

Answers

Answer:

x = 11, y = 17

Step-by-step explanation:

Set the equations equal to each other. Since the vertical angles are congruent, 8x + 7 = 9x - 4 and 5y = 7y - 34. Now, solve your equations for the x and y values.

8x + 7 = 9x - 4

x = 11

5y = 7y - 34

2y = 34

y = 17

Please help its vocab matching

Answers

Answer:

1. S

2. G

3. I

4. O

5. P

6. D

7. C

8. F

9. J

10. Q

11. E

12. K

13. R

14. A

15. B

16. N

17. M

18. L

19. H

Step-by-step explanation:

4. O

→ 3 is a coefficient of 3x

5. P

→ 3 is a common factor in the expression 3x+9

6. D

→example of a constant term is 1,3,10

7. C

→ [tex]cosx=\frac{adjacent}{hypotenuse} =\frac{A}{H}[/tex]

8. F

→[tex]x^{2} -4[/tex] will be factorised as (x-2)(x+2)

9. J

→ example of an expression is [tex]2x+9[/tex]

10. Q

→ factors of 3 are 3×1.

11. E

→ example of factoring is [tex](x+2)(3x+4)[/tex]

12. K

→ example of a factored completely is [tex]2x(x+y)[/tex]

14. A

→example of a polynomial is [tex]3yx^{3} +xy^{2} -2x+9[/tex].

15. B

→ example of a quadratic expression is [tex]x^{2} +6x-9[/tex].

17. M

→ [tex]sinx=\frac{opposite}{hypotenuse} =\frac{O}{H}[/tex]

18. L

→ [tex]tanx=\frac{opposite}{adjacent} =\frac{O}{A}[/tex]

19. H

→ example of a term is 2x,3,40

Write an equation of a line parallel to the line below in point-stope form that passes through the point (-1,5).
y = 1/4x - 6
y + 1 = - 4(x - 5)
y + 1 = 1/4(x - 5)
y - 5 = 1/4(x + 1)
y- 5 = - 4(x + 1)

Answers

y+1=1/4(x-5)



This should be the right answer

Find the common ratio of the geometric sequence 2,-6,18,...

Answers

Answer: -3

Step-by-step explanation:

Use the ratio r= a2/a1

So -6/2= -3

2*-3=-6

-6*-3= 18

18*-3= -54

Simplify (x^2/7)^3/4

Answers

Answer:

(x^2)^(3/4)/7^(3/4)

Step-by-step explanation:

Which is a factor of the polynomial f(x) = 6x4 – 21x3 – 4x2 + 24x – 35?

Answers

Answer:

If a polynomial function has integer coefficients, then every rational zero will have the form pq p q where p p is a factor of the constant and q q is a factor

Step-by-step explanation:

Using synth. div. to check whether or not 7/2 is a root:

        ___________________________

7/2   /   6    -21    -4    24    -35

                  21      0   -14     35          

       ----------- ------------------------------

          6        0     -4    10       0

Because the remainder is zero, 7/2 (or 3.5) is a root of the polynomial.  Thus, (x-3.5), or (x-7/2), is a factor.

5. If you receive 24% off of a $100.00 item, what is the final price of the item?
A. $0.24

Answers

Answer:

24% of 100 is 24 meaning you subtract 24 to 100. Giving you $76 as the final price.

Step-by-step explanation:

question 9 i mark as brainliest ​

Answers

Answer:

I think the third one I'm not sure tho

Answer:95,826

Step-by-step explanation:

2. Find the distance between (-2,1) and (3,4).

Answers

Answer:

[tex]\sqrt{34}[/tex] or 5.83095

Step-by-step explanation:

Use the distance formula [tex]\sqrt{(x_{2}-x_{1} )^{2}+(y_{2}-y_{1} )^2 }[/tex]

Make sure to round the answer appropriately if not asked for in square root form!!

.
Jamie went shopping for party snacks. He bought 3 bags of chips for $4.00 each, 5 bottles of soda for $2.00 each and an ice cream cake for $20.00. How much did he spend altogether?
Choose the expression that is a correct translation of the problem.
(3 x 4) x (5 x 2) + 20
(3 + 4) + (5 + 2) + 20
(3 x 4) + (5 x 2) + 20
(3 x 4) + (5 x 2) x 20

Answers

Answer:

C (3x4) + (5x2) + 20

Step-by-step explanation:

3 things that cost 4 dollars. 5 things that cost 2 dollars and one that cost 20.

Find the distance between each pair of points. Round your answer to the nearest tenth, if necessary. ​

Answers

I don’t really understand I need more detail

Which expression shows the ASSOCIATIVE PROPERTY?
3 + a + b = a + 3 + b
3(ab) = (3a)b
(3 + a) + b = 3 + (a + b)
3 - a = 3 - b

Answers

Answer:

the first one

Step-by-step explanation:

what is the value of n n+11=13​

Answers

Answer:

n = 2

Step-by-step explanation:

[tex]n + 11 = 13[/tex]

Subtract 11 from both sides to isolate n.

[tex]n + 11 - 11 = 13 - 11[/tex]

[tex]n = 2[/tex]

Kylie is shopping at the mall. She buys a pack of water balloons for $3. She also buys seven t-shirts, each marked at the same price. Kylie spends a total of $59

Identify which equation models this situation.

a.3x+7=59
b.3x+7y=59
c.3x+7x=59
d.7x+3=59

Answers

Answer:

b 3x +7y =59

Step-by-step explanation:

x is water balloons at 3 each and y is t-shirts at 7$ each.

How is dividing and multiplying with an area model similar and How is it different?

Answers

Answer:

In multiplication the numbers you multiply are called factors; the answer is called the product. In division the number being divided is the dividend, the number that divides it is the divisor, and the answer is the quotient.

If LN = 6x - 5, LM = x + 7, and MN = 3x + 20, find MN.
A.68
B.16
C.23
D.18

Answers

Answer : The correct option is (A) 68.

Step-by-step explanation :

As we are given that:

LN = 6x - 5

LM = x + 7

MN = 3x + 20

Now we have to determine the value of MN.

According to the question:

LN = LM + MN

Now putting all the given values in this expression, we get:

6x - 5 = (x + 7) + (3x + 20)

6x - 5 = 4x + 27

6x - 4x = 27 + 5

2x = 32

x = 16

The value of MN = 3x + 20 = 3(16) + 20 = 48 + 20 = 68

Therefore, the value of MN is 68.

Anna takes 10 selfies every 12 minutes at this rate how many minutes for 25 selfie’s

Answers

Answer:

30 minutes.

Step-by-step explanation:

You can make a proportion, which would be 10 selfies : 12 minutes. The second one will be 25 selfies : x minutes.

They have to be equal, since it is given that the rate stays the same. So 10:12=25:x

A proportion can be written as a fraction, so 10/12=25/x.

Cross multiply, and you get 10*x=12*25, or 10x=300.

Now divide both sides by 10 to get x=30.

50 POINTS SOLVE !! ::

pls actually solve it thank you <3

k-4 /9 =3

8+b /-4 = -5

Answers

Answer:

k = 31/9b = 12

Step-by-step explanation:

k - 4 = 3

   9

k/9  = 3(9) + 4

k = 31/9

k = 31/9

8 + b = -5

  -4

8 + b = -5 (-4)

8 +  b = 20

b = 20 - 8

b = 12

Question 5: What is the equation of the line parallel to x = 7, passing through the point (-4, 1)?
A. X = -4
B. X = 1
C. Y = -4
D. Y = 1

Answers

Answer:

(A) x= -4

Step-by-step explanation:

The question requires you to find the equation of the line parallel to x=7

Line x=7 is a vertical line crossing the x-axis at x=7

A vertical line has undefined slope, no slope

However, parallel lines are those that do not meet and has the same slope. This means you should expect that the equation required should also have an undefined slope, slope of zero.

The line will pass through point (-4,1) and be a vertical line.

The equation of the line will be: x= -4

A city has a population of 38802500 people. Estimate this population to the nearest ten million

Answers

Answer:

40,000,000 or 40 million

Step-by-step explanation:

a metal plate, with constant density 5 g/cm^2, has a shape bounded by the curbe y = x^2 and the x-axis, with 0<= x <= 3 and the x, y in cm

a) find the total mass of the plate
mass =

b) sketch the plate. using your sketch, is x less than or greater than 3/2?

c) find x
x =

Answers

Answer:

a) 45 g

b) greater (make the graph youself on desmos or something)

c) 9/4

Step-by-step explanation:

area = integral 0 to 3 of x^2 dx = [1/3x^3] 0 to 3 = 9

mass = density * area = 5 * 9 = 45 grams

area = y*deltax = x^2*deltax

x = integral 0 to 3 of 5x^3 dx / mass = (405/4) / 45 = 9/4

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