In the U.S., 20% of adults ages 25 and older have never been married, more than double the figure recorded for
1960. Select a random sample of 50 U.S. adults ages 25 and older and let X = the number of individuals in the
sample who have never married. Use for problems 1 - 4.
1. Calculate the mean and standard deviation of the sampling distribution of X.
2. Interpret the standard deviation.
3. Justify that the sampling distribution of X is approximately normal.
4. Calculate the probability that at least 13 of the people in the sample have never been married and are 25 and older, then interpret the meaning of this probability in context of the problem.
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