Homework Help: Statistics

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: ľ = 124 -->null hypothesis
Ha: ľ > 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 - An automobile in surer has found that repair claims have a mean of...
statistics - You are the owner of an auto repair service. History tells you it ...
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 ...
Statistics - A computer repair service found that a random sample of 45 repair ...
Math-Advanced Pre-Algebra - A computer repair shop charges a flate rate of 50$ ...
statistics - A manufacturer of luxury SUVs is concerned because warranty claims ...
Math - A motorist averages 30 kph on ordinary loads and 12 kph on roads under ...
stats - An automobile repair shop has determined that the average service time ...
math - The dance company has a $10 cover charge, an average of 200 people will ...

For Further Reading

First Name:
School Subject:
Answer: