Posted by **lola** on Thursday, April 19, 2012 at 5:13pm.

A large television repair service claims that its average repair charge is $124. Suspecting that the average charge is higher, a consumer group randomly choose a sample of 35 statements for tv repairs done by the repair service and found the mean was $125.50 and s = 2.25. Test the claim at the .05 level of significance

- Statistics -
**MathGuru**, Thursday, April 19, 2012 at 6:18pm
Use a one-sample z-test.

Hypotheses:

Ho: µ = 124 -->null hypothesis

Ha: µ > 124 -->alternate hypothesis

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

With your data:

z = (125.50 - 124)/(2.25/√35) = ?

Finish the calculation.

Check a z-table at .05 level of significance for a one-tailed test.

If the z-test statistic exceeds the critical value from the z-table, reject the null. If the z-test statistic does not exceed the critical value from the z-table, do not reject the null.

I hope this will help get you started.

## Answer This Question

## Related Questions

- statistics - You are the owner of an auto repair service. History tells you it ...
- Statistics - A computer repair service found that a random sample of 45 repair ...
- Algebra - a car repair shop charge $80 per hour for labor and $210 for the parts...
- statistics - An appliance repair shop owner has fitted the quadratic trend ...
- Probability - You are the owner of an auto repair service. History tells you it ...
- Operations management - An appliance manufacturer wants to contract with a ...
- math - A small business just leased a new computer and color laser printer for ...
- stats - An automobile repair shop has determined that the average service time ...
- Statistics - Computer Depot is a large store that sells and repairs computers. A...
- Statistics - A recent article in the Myrtle Beach Sun Times reported that the ...

More Related Questions