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The Sampling Distribution of a Sample Mean

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 \(0.8614\).