Sampling Distribution of Difference Between Means

Answers

  1. The mean of the distribution of the difference between sample means is equal to the difference between population means. 20 - 15 = 5

  2. The variance of the sampling distribution of the difference between means is equal to the variance of the sampling distribution of the mean for Pop 1 plus the variance of the sampling distribution of the mean for Pop 2. 100/20 + 64/16 = 5 + 4 = 9

  3. Mean = 10, SD = 4, Plug these into the normal calculator and find the area above 6. You get. 841. A similar question using this data appears in the text.

  4. Mean = 727 - 532 = 195, Var = 12,000/12 + 10,000/14 = 1,714.3, SD = sqrt(1,714.3) = 41.404, Use the normal calculator to calculate the area above 150 for a distribution with this mean and SD. You get 0.8614.