# Question

The formula for the pooled variance, s2p, is given on page 397. Show that, if the sample sizes, n1 and n2, are equal, then s2p is the mean of s21 and s22.

## Answer to relevant Questions

In this exercise, you are to perform a computer simulation to illustrate the distribution of the pooled t-statistic, given in Key Fact 10.2 on page 397. a. Simulate 1000 random samples of size 4 from a normally distributed ...Suppose that you want to perform a hypothesis test to compare the means of two populations, using independent simple random samples. Assume that the two distributions (one for each population) of the variable under ...x1 = 20, s1 = 4, n1 = 10, . x2 = 23, s2 = 5, n2 = 15 a. Left-tailed test, α = 0.05 b. 90% confidence interval We have provided summary statistics for independent simple random samples from two populations. In each case, ...D. Cristol et al. published results of their studies of two subspecies of dark-eyed juncos in the article "Migratory Dark-Eyed Juncos, Junco Hyemalis, haveBetter Spatial Memory and Denser Hippocampal Neurons than ...In Exercise 10.73, you conducted a nonpooled t-test to decide whether the mean number of acute postoperative days spent in the hospital is smaller with the dynamic system than with the static system. a. Using a pooled ...Post your question

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