1. Answer the following True or False:

Suppose a sample size of 87 was used to conduct a right tailed hypothesis test for a single population mean. The null hypothesis was H₀:= 45and the sample mean was 50 and the p-value was 0.03. Then there is a 3% chance that 87 randomly selected individuals from a population with a mean of 45 and the same standard deviation would have a sample mean greater than 50.

• false
• true

2. Answer the following True or False:

If a police officer wants to find out whether the average speed of motorists on a highway with a speed limit of 55 mph is greater than 55 mph, then the null hypothesis is 55.

• true
• false

3. A commonly cited standard for one-way length (duration) of school bus rides for elementary school children is 30 minutes.

A local government office in a rural area conducts a study to determine if elementary schoolers in their district have a longer average one-way commute time. If they determine that the average commute time of students in their district is significantly higher than the commonly cited standard they will invest in increasing the number of school buses to help shorten commute time. What would a Type 2 error mean in this context?

• The local government decides that the average commute time is 30 minutes.
• The local government decides that the data provide convincing evidence of an average commute time higher than 30 minutes, when the true average commute time is in fact 30 minutes.
• The local government decides that the datado notprovide convincing evidence of an average commute time higher than 30 minutes, when the true average commute time is in fact higher than 30 minutes.
• The local government decides that the datado notprovide convincing evidence of an average commute time different than 30 minutes, when the true average commute time is in fact 30 minutes.

4. A 2011 survey, by the Bureau of Labor Statistics, reported that 91% of Americans have paid leave. In January 2012, a random survey of 1000 workers showed that 89% had paid leave.

The resulting p-value is 0.0271; thus, the null hypothesis is rejected. It is concluded that there has been a decrease in the proportion of people, who have paid leave from 2011 to January 2012.

What type of error is possible in this situation?

• type I
• type II
• neither
• both

5. A researcher looks at the mean salaries of male and female electricians and decides based on the evidence that there is no difference between the two groups. The researcher could have made aSelect an answer Type I Error/ Type II Error

in drawing this conclusion.