Q:

About 77% of young adults think they can achieve the American dream. Determine if the following statements are true or false, and explain your reasoning.(a) The distribution of sample proportions of young Americans who think they can achieve the American dream in samples of size 20 is left skewed.(b) The distribution of sample proportions of young Americans who think they can achieve the American dream in random samples of size 40 is approximately normal since (n) equal or bigger then 30.(c) A random sample of 60 young Americans where 85% think they can achieve the American dream would be considered unusual.(d) A random sample of 120 young Americans where 85% think they can achieve the American dream would be considered unusual.

Accepted Solution

A:
Answer:Step-by-step explanation:Given that about 77% of young adults think they can achieve the American dream.We find that here X the no of young adults who think they can  achieve the American dream has two outcomes and each person is independent of the other.X is binomial.  When X is approximated to binomial, the condition are sample size should be large and also the probability p for each trial success should be near 1/2Hence we find that when prob is 0.85 the approximation will not be reasonable.  But if both np and nq are greater than 5 we can approximatenp = 51 nq =9 both greater than 5Similarly for 120 also both np and nq >5b) The distribution of sample proportions of young Americans who think they can achieve the American dream in random samples of size 40 is approximately normal since (n) equal or bigger then 30.(c) A random sample of 60 young Americans where 85% think they can achieve the American dream would be considered unusual.(d) A random sample of 120 young Americans where 85% think they can achieve the American dream would be considered unusual.These are true.