Need help with these anwsers . In order for me to recieve the full credit for these questions I need full work shown .

Fall 2020

Exam 3

MA-336

Name:

You must SHOW ALL WORK on this exam to receive partial credit for

incorrect answers, or ANY credit for correct answers.

Make sure your work is organized and legible. I will not give credit to

solutions I cannot read. Please put a circle or box around your final answer.

Be sure to read each question carefully.

You do NOT have to print out the exam. You may write your exam on

ordinary paper. To make sure your writing is normal size, use a scanner app

like Office Lens (which works for all smartphones) or Evernote Scannable

(which works for iPhones or iPads) to convert your handwritten exam to

a PDF file for upload to Blackboard Assignments. Note: Office Lens and

Evernote Scannable are both FREE to download. If your submission is not

readable, you will lose points.

When you submit your exam, be careful with the file name. Every file name

has an extension which specifies the format or type of file. Examples of file

extensions are pdf, jpg, and docx. The file extension appears to the right of

the period. Do NOT type anything to the right of the period which would

alter the file extension. Doing this will make the file unreadable. For example,

Exam2.pdf is an acceptable file name whereas Exam2.pdf1 renders the file

unreadable until the Ã¢â‚¬Å“1Ã¢â‚¬Â is deleted.

Question:

1

2

3

4

5

6

7

8

9

Total

Points:

10

10

10

10

10

10

12

12

16

100

Score:

Exam 3

MA-336

Fall 2020

1. Consider the following ordered pairs:

(Ã¢Ë†â€™2, Ã¢Ë†â€™6.2), (1, 7.2), (4, 17.4), (7, 14.5)

(i) Calculate the linear correlation coefficient r. Is the correlation strong?

(ii) Compute the regression line.

(iii) Use the regression line to estimate the y-coordinate when x = 6.

Exam 3

MA-336

Fall 2020

2. In the US, the shoe size of women is normally distributed with mean 8 inches and a

standard deviation of 1.5 inches.

(i) What is the percentage of women in the US with shoe size between 6 inches and

10 inches?

(ii) What is the percentage of women with shoe size greater than 10.5 inches?

3. The weight of a new species of wolf is normally distributed with a mean weight of

Ã‚Âµ = 160 lbs and a standard deviation of ÃÆ’ = 25 lbs. This new species of wolf has

been called a blue wolf. What is the 80th percentile for the weight of the blue wolf?

Exam 3

MA-336

Fall 2020

4. The average height of redwood trees in the Pacific Northwest is 360 feet with a

standard deviation of 80 feet. A sample of 35 redwood trees is selected. Let x denote

the mean height of the sample.

(i) What is the probability that x is between 350 feet and 380 feet?

(ii) What is the probability that x is greater than 395 feet?

Exam 3

MA-336

Fall 2020

5. In the US, 29% of the population suffers from back pain. 140 people are chosen at

random. Let pb be the proportion of the sample with back pain. What is the probability that pb will between 25% and 32%?

6. Greyhound bus says they arrive at their destination on time 90% of the time. In a

random sample of 230 Greyhound buses, it was found that only 200 arrive on time.

(i) Assuming GreyhoundÃ¢â‚¬â„¢s claim is true, compute the probability of getting a sample

of size 230 with a sample proportion as low as the one observed in this sample.

(ii) Based on your calculation in (i), do you believe GreyhoundÃ¢â‚¬â„¢s claim?

Exam 3

MA-336

Fall 2020

7. A new surgical procedure for repairing disc herniations is developed. In a random

sample of 150 of these operations, 104 were a success. Calculate the 96% confidence

interval for the proportion of these types of operations which were a success.

8. A sample of 40 female giraffes are chosen. The mean height is found to be 15 feet.

Assume that the population standard deviation for the height of female giraffes is

ÃÆ’ = 5 feet. Calculate the 95% confidence interval of for population mean height of

female giraffes.

Exam 3

MA-336

Fall 2020

9. In a random sample of 20 male grizzlies, the sample mean was found to be 550 pounds

and the sample standard deviation was found to be 30 pounds. Calculate the 90%

confidence interval for the population mean weight of male grizzlies. Assume that the

weight of male grizzles are normally distributed.

Purchase answer to see full

attachment