Suppose that a researcher wants to check to see if the average household income in
Webster Groves,Missouri,has changed from the $60,000 it was three years ago.The
Researcher takes a random sample of households in Webster Groves and finds that the average income of these households is $58,000.If the standard error of the mean for this sample is $500,what is the approximate conclusion produced by the Z-test if the critical Z-value is 1.96?
A)Accept the null hypothesis
B)Reject the research hypothesis of interest
C)Accept the hypothesis of the status quo
D)Reject the null hypothesis and accept the research hypothesis
E)Reject the research hypothesis

Question

Quizplus · Accepted Answer

The Z-test is used to determine if there is a significant difference between the sample mean and the population mean. The Z-score is calculated as (58000 - 60000) / 500 = -4. Since -4 is less than -1.96, we reject the null hypothesis, indicating a significant change in average household income.

Suppose That a Researcher Wants to Check to See If