Posted by **Michelle** on Thursday, September 11, 2008 at 1:29am.

Hello I need help solving a statistics problem and have no idea where to start. Can anyone help?

In a recent national survey, the mean weekly allowance for a nine-year-old child from his or her parents was reported to be $3.65. A random sample of 45 nine-year-olds in northwestern Ohio revealed the mean allowance to be $3.69 with a standard deviation of .24. At the .05 level of significance, is there a difference in the mean allowances nationally and the mean allowances in northwestern Ohio for nine-year-olds?

- Statistics -
**MathGuru**, Thursday, September 11, 2008 at 8:53am
Try a one-sample z-test for your problem.

Using the z-test formula to find the test statistic:

z = (sample mean - population mean)/(standard deviation divided by the square root of the sample size)

z = (3.69 - 3.65)/(.24/√45)

Finish the calculation. Use a z-table to determine the critical or cutoff value to reject or fail to reject the null hypothesis at .05 level of significance. This will be a two-tailed test because the problem is just asking if there is a difference. Keep that in mind when you are looking at the value in the table.

Once you have the value from the table, compare to the test statistic. If the test statistic exceeds the value from the table, reject the null and conclude a difference. If the test statistic does not exceed the value from the table, fail to reject the null and you cannot conclude a difference.

I hope this will help get you started on your problem.

## Answer this Question

## Related Questions

- Statistics - 3. The average weekly allowance of students last year at a private ...
- statistics - A physician routinely makes physical examinations of children. She ...
- math - mario got his $10.00 weekly allowance on monday. he spent 25% of his ...
- math - Mario got his $10.00 weekly allowance on Monday. He spent 25% of his ...
- 4 grade - Mario got his $10.00 weekly allowance on Monday. He spent 25% of his ...
- statistics - Scores on a recent national statistics exam were normally ...
- concept development - Choose the best example of a specific task assessment. A. ...
- Child care - An encyclopedia on CD-ROM would be most appropriate for a typical A...
- Statistics - 1200 high school freshman were randomly selected for a national ...
- Statistics - A simple random sample of 50 female 14-year-olds is selected. The ...