A Gallup survey found the mean charitable contribution on federal tax returns was $1025 (

USA

Tomorrow

, April 10, 2000). Assume a sample

of April 2001 tax returns will be used to conduct a

hypothesis test designed to determine whether any change has occurred in the mean charitable

contributions.

a.

Formulate the null and alternative hypotheses.

b.

Assume that a sample of 250 tax returns has

a sample mean of $1100 and a sample

standard deviation of $865. What is the value of the test statistic?

c.

What is the

p

-

value?

d.

Using

a

= .05, what is your conclusion?

e.

If you use the critical value approach, what would your critical value be?