# Question: A variable of two populations has a mean of 40

A variable of two populations has a mean of 40 and a standard deviation of 12 for one of the populations and a mean of 40 and a standard deviation of 6 for the other population.

a. For independent samples of sizes 9 and 4, respectively, find the mean and standard deviation of x1 − x2.

b. Must the variable under consideration be normally distributed on each of the two populations for you to answer part (a)? Explain your answer.

c. Can you conclude that the variable x1 − x2 is normally distributed? Explain your answer.

a. For independent samples of sizes 9 and 4, respectively, find the mean and standard deviation of x1 − x2.

b. Must the variable under consideration be normally distributed on each of the two populations for you to answer part (a)? Explain your answer.

c. Can you conclude that the variable x1 − x2 is normally distributed? Explain your answer.

## Answer to relevant Questions

A variable of two populations has a mean of 7.9 and a standard deviation of 5.4 for one of the populations and a mean of 7.1 and a standard deviation of 4.6 for the other population. a. For independent samples of sizes 3 and ...Regarding the four conditions required for using the pooled t-procedures: a. What are they? b. How important is each condition? 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, use ...In the article "Floral Diversity in Relation to Playa Wetland Area and Watershed Disturbance" (Conservation Biology, Vol. 16, Issue 4, pp. 964-974), L. Smith and D. haukos examined the relationship of species richness and ...Philosophical and health issues are prompting an increasing number of Taiwanese to switch to a vegetarian lifestyle. In the paper "LDL of Taiwanese Vegetarians Are Less Oxidizable than Those of Omnivores" (Journal of ...Post your question