The average retirement age for a certain country was reported to be

58.7

years according to an international group dedicated to promoting trade and economic growth. With the pension system operating with a deficit, a bill was introduced by the government during the summer to raise the minimum retirement age from 60 to 62. Suppose a survey of

35

retiring citizens is taken to investigate whether the new bill has raised the average age at which people actually retire. Assume the standard deviation of the retirement age is

4

years. Using

=0.10,

answer parts a through c below.

a. Explain how Type I and Type II errors can occur in this hypothesis test.

A Type I error can occur when the researcher concludes the average retirement age

increased,

but the average retirement age

did not increase.

A Type II error can occur when the researcher concludes that the average retirement age

did not increase,

when, in fact, the average retirement age

increased.

b. Calculate the probability of a Type II error occurring if the actual population age is

60.0

years old.

The probability of committing a Type II error is

enter your response here.