1. X-bar is an unbiased estimator of µ because a. standard error of X-bar equals sigma/...

1. X-bar is an unbiased estimator of µ because

a. standard error of X-bar equals sigma/ square root of n

b. expected value of X-bar equals µ

c. shape of distribution of X-bar is normal.

d. Expected value of X-bar is greater than 1.

2. Suppose professor finds that for 16 randomly selected students the time needed to complete an assignment had a sample mean of 65 minutes and a sample standard deviation of 40 minutes. The 98% confidence interval estimate for the population mean is:

3. The starting salaries of individuals with an MBA degree are normally distributed with a mean of $90,000 and a standard deviation of $20,000. Suppose we randomly select 16 of these individuals with an MBA degree. What is the probability that the average starting salary for these individuals is at least $85,800? 0.7995 0.9131 0.2005 -0.2611

4. The probability P(0 <= Z <= 1.63) is:

a. 0.4265

b. 0.9484

c. 0.5071

d. 0.4484

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Expert Solution

orchestra answered 2 years ago

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