A Gallop survey found the mean charitable contribution on federal tax returns was $1075. Assume a sample of 2012 tax returns is used to conduct a hypothesis test to determine whether any change occurred in the mean charitable contributions.
i. Formulate null and alternative hypotheses.
ii. Using ? = 0.05, Determine the critical value for the test statistic? State the rejection rule.
iii. Suppose that sample of 200 tax returns shows sample mean of $1160 and sample standard deviation of $840. Determine the value of the test statistic?
iv. Using the p-value what is your conclusion?