Post a New Question


posted by on .

a study of the amount of time it takes a mechanic to rebuild the transmission of a 1992 chevrolet cavalier shows that the mean is 8.4 hours and the standard deviation is 1.8 hours. if 40 mechanics are randomly selected, find the probability that their mean rebuild time exceeds 8.7 hours.

  • stats - ,

    Z = (mean1 - mean2)/standard error (SE) of difference between means

    SEdiff = √(SEmean1^2 + SEmean2^2)

    SEm = SD/√(n-1)

    Since only one SD is provided, you can use just that to determine SEdiff.

    Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to that Z score.

Answer This Question

First Name:
School Subject:

Related Questions

More Related Questions

Post a New Question