Chapter 9 Assignment 1 2020

Problem 1: Dole Pineapple Inc. is concerned that the 16-ounce can of sliced pineapple is being overfilled. Assume the population standard deviation of the process is .03 ounces. The quality-control department took a random sample of 70 cans and found that the arithmetic mean weight was 16.05 ounces. At the 5% level of significance, can we conclude that the mean weight is greater than 16 ounces?

1. Identify Null and Alternate Hypothesis
2. Identify the Test Statistic (Z-Value) statistic
3. Determine the p-value.
4. What is the decision - Reject or Not reject and why

Problem 2: The post anesthesia care area (recovery room) at St. Luke's Hospital in Maumee, Ohio, was recently enlarged. The hope was that with the enlargement the mean number of patients per day would be more than 25. A random sample of 15 days revealed the following numbers of patients.

25

25

24

24

25

25

25

25

26

25

26

26

24

26

25

At the .01 significance level, can we conclude that the mean number of patients per day is more than 25?

1. Identify Null and Alternate Hypothesis
2. Identify the test statistic (t value) statistic
3. Estimate the p-value and interpret it. (Reject or Not Reject and why)

Problem 3: Research in the gaming industry showed that 10% of all slot machines in the United States stop working each year. Short's Game Arcade has 70 slot machines and only 3 failed last year. Use the five-step hypothesis-testing procedure at the .05 significance level to test whether this data contradicts the research report.

1. Why can you employ Z as the test statistic?
2. State the Null and Alternate Hypotheses.
3. Evaluate the test statistic and make the decision.
4. What is the p-value and does that support your conclusion in C? and why

Problem 4:Consider the following hypothesis test: (12)

H₀: u = >= 80

H_a: u = < 80

A sample of 100 is used and the population standard deviation is 12. Compute the critical value or p-value as asked and state your conclusion for each of the following sample results. Use = .01.

a. X_bar = 78.5 - p-value

b. X_bar = 77 - critical value

c. X_bar = 75.5 - p-value

d. X_bar = 81 - critical value

Problem5: Consider the following hypothesis test: (26)

H₀: u = 100

H_a: u <> 100 (Note: <> is not equals

A sample of 65 is used. Identify the p-value and state your conclusion for each of the following

sample results. Use = .05.

a. X_bar = 103 and s= 11.5

b. X_bar = 96.5 and s= 11.0

c. X_bar = 102 and s= 10.5