Question 981085: The hourly rate of janitors in a city had a mean of $15 and standard deviation rate of $3 in the past. In a recent random sample of 36 janitors, the mean hourly rate was 16.5. Perform the test of hypothesis to investigate whether the mean hourly rate for janitors has changed in the city. Use 0.05 level of significance.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! The hourly rate of janitors in a city had a mean of $15 and standard deviation rate of $3 in the past. In a recent random sample of 36 janitors, the mean hourly rate was 16.5. Perform the test of hypothesis to investigate whether the mean hourly rate for janitors has changed in the city. Use 0.05 level of significance.
================
Ho: u = 15
Ha: u # 15 (claim)
----------------------
x-bar = 16.5
test stat:: z(16.5) = (16.5-15)/[3/sqrt(36)] = 1.5/(1/2) = 3
------
p-value = 2*P(z > 3 ) = 2*normalcdf(3,100) = 2*0.001 = 0.002
-----
Conclusion:: Since the p-value is less than 5%, reject Ho.
Conclusion:: The test results support the claim that u # 15.
-----------
Cheers,
Stan H.
------------
|
|
|
