1. Suppose that 4% of American adults are currently unemployed. Find the probability that in a random sample of 625 American adults, at most 30 are unemployed.

2. The percentage of children who leave foster care due to adoption is generally accepted to be 15%. A social worker claims that this percentage is incorrect. After performing a hypothesis test on his claim using sample data from 2009, he fails to reject the null hypothesis. According to the US Dept. of Health and Human Services, the actual percentage was 20% in 2009. Was an error made? If so, what type?

3. According to a study from 2013, 60% of Americans get 7 or more hours of sleep per night. Suppose in a recent sample of 340 Americans it was found that 55% of them get 7 or more hours of sleep per night. Do the sample data provide evidence that the proportion of Americans who get 7 or more hours of sleep per night has decreased? Test the relevant hypotheses at a significance level of = 0.05.