Question

State the null (H₀) and alternative (H_a) hypothesis for each of the following cases:

a.) An investigative reporter for the Chicago Tribune reports that the average spending by American adults during the six-day period after Thanksgiving, spanning Black Friday weekend through Cyber Monday, is $100. You decide to conduct a hypothesis test to verify this report.

b.) The average wait time at an ER is known to be 128 minutes. A local newspaper claims that the average wait time at this ER has increased greatly from 128 minutes.

c.) Suppose a manufacturer of batteries claims that the average capacity of a certain type of battery the company makes is at least 140 ampere-hours. Recently there have been complaints that the average capacity is less than the claim.

d.) You want to test to see if there is a difference between the average fuel efficiency of cars with automatic and manual transmissions in terms of their average city mileage (in miles per gallon). Where µ1 is the average fuel efficiency of cars with automatic transmission and µ2 is the average fuel efficiency of cars with manual transmission.

e.) A study claims that adults watch television an average of 1.8 hours a day. What alternative hypothesis would you use if you think this figure is too low?

f.) A coffee shop manager reads that the average preferred temperature for coffee among the US population is 110 degrees F. However, the manager at the coffee shop does not believe this is true for his customers and wants to test this by surveying them.

Answer 1

(a) H0: Null Hypothesis: = 100

Ha: Alternative Hypothesis:

(b) H0: Null Hypothesis: = 128

Ha: Alternative Hypothesis: > 128

(c)H0: Null Hypothesis: 140

Ha: Alternative Hypothesis: < 140

(d) H0:Null Hypothesis:

Ha: Alternative Hypothesis:

(e) H0: NullHypothesis: = 148

Ha: Alternative Hypothesis: < 148

(f) H0: Null Hypothsis: = 110

Ha: Alternative Hypothesis: 100