A sample of 40 observations is selected from one approximately normal population. The sample mean is 102 and the sample standard deviation is 5. A sample of 50 observations is selected from a second source. The sample mean is 99 and the standard deviation is 6. Conduct a hypothesis test using the .04 level of significance to determine if there is a difference between the population means

Question

A sample of 40 observations is selected from one approximately normal population.  The sample mean is 102 and the sample standard deviation is 5.  A sample of 50 observations is selected from a second source.  The sample mean is 99 and the standard deviation is 6. Conduct a hypothesis test using the .04 level of significance to determine if there is a difference between the population means

PsyDAG · Answer

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

SEdiff = √(SEmean1^2 + SEmean2^2)

SEm = SD/√(n-1)

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