1. The average 1-year-old girl is 25 inches tall. A random sample of 40 one-year-old-girls in a large day care
franchise had an average height of 25.5 inches. At a=0.05,
can it be concluded that the average height differs from 25 inches?
Assume ?=1.96.

The alternative hypothesis?

Critical Value?

Computed Test Value?

The decision?

Evidence?

2. A researcher estimates that the average height of the buildings of 30
or less stories in a large city is less than 750 feet.
A random sample of 10 buildings is selected and the results are as follows:
=700 ; =55 . At a=0.025, is there enough evidence to support the claim?

Critical Value?

value of the t-test statistic obtained from the sample?

Decision?

Evidence?

3. Men spend an average of 21 minutes per day on weekends reading.
A random sample of 20 men resulted in a mean of 18 minutes reading with
a standard deviation of 7 minutes. At a = 0.05, is there
sufficient evidence that these results differ from the national mean?

Critical Value?

value of the t-test statistic obtained from the sample?

Decision?

Evidence?