Answer
a. $H_{o}: μ = 17,072$
$H_{1}: p \ne 17,072$
b. Type-I Error: Sample evidence leads researchers to believe that the mean has changed. However, in fact it has not changed.
c. Type-II Error: Sample evidence leads researchers to believe that the mean has not changed. However, in fact it did change.
Work Step by Step
a. Null hypothesis (mean charitable contribution remains at $\$17,072$):
$H_{o}: μ = 17,072$
Alternative hypothesis (mean charitable contribution has changed):
$H_{1}: p \ne 17,072$
b. Type-I Error: Sample evidence leads researchers to believe that the mean has changed. However, in fact it has not changed. In other words, the scientists have rejected the null hypothesis ($H_o$), but it in fact is true.
c. Type-II Error: Sample evidence leads researchers to believe that the mean has not changed. However, in fact it did change. In other words, the scientists have not rejected the null hypothesis ($H_o$), when in fact the alternative hypothesis ($H_1$) is true.
