1. Single adults: According to a Pew Research Center analysis of census data, in 2012, 20% of American adults ages 25 and older had never been married. Suppose that we select random samples from this population of American adults ages 25 and older. For each sample we then calculate the proportion that had never been married. (Source: Wang, W., and Parker, K. (2014). Record Share of Americans Have Never Been Married. Pew Research Center.)For which of the following sample sizes will the sampling distribution be approximately normal? Check all that apply.

• 25
• 50
• 75

2. Single adults: According to a Pew Research Center analysis of census data, in 2012, 20% of American adults ages 25 and older had never been married. If we randomly sample 100 adults from this population, would it be unusual to see a sample with 13% who had never been married?

• Yes, this is unusual because we expect the sample proportion to be 20%.
• Yes, this is unusual because the sample proportion has a 7% error which is more than the standard error of 4%.
• No, this is not unusual because 13% is less than 2 standard deviations from 20%.
• No, this is not unusual because we expect the sample proportions to vary from 20%.

3. Obesity:The National Center for Health Statistics conducted the National Health Interview Survey (NHIS) for 27,787 U.S. civilian noninstitutionalized adults in January-September 2014. According to an early release report, an estimated 29.9% of U.S. adults aged 20 and over were obese. Obesity is defined as a body mass index (BMI) of 30 kg/m²or more. True or false? The 29.9% is a parameter representing a population of 27,787 adults.

4. Single adults: According to a Pew Research Center analysis of census data, in 2012, 20% of American adults ages 25 and older had never been married. (Source: Wang, W., and Parker, K. (2014). Record Share of Americans Have Never Been Married. Pew Research Center.)

If we repeatedly obtain random samples of 50 adults, what is the standard deviation of the sampling distribution of sample proportions? Enter your answer in decimal form rounded to two decimal places.

5. Blue M&M's: The M&M's website says that 24% of milk chocolate M&M's are blue. Suppose that we buy 5 small packets of milk chocolate M&M's. Each packet contains 55 candies. Which sequence is the most likely for the percent of blue M&M's in these 5 packets?

• 24%, 24%, 24%, 24%, 24%
• 20%, 24%, 31%, 27%, 36%
• 6%, 24%, 42%, 9%, 44%
• Any of the other lists because the samples are random.

6. Research in 2018 suggests that 40% of U.S. school teachers feel that their schools are not well prepared to prevent a shooting.

We randomly sample 50 U.S. school teachers and find that 46% say that their schools are not well prepared to prevent a shooting.

What is the probability that a random sample of 50 teachers has more than 46% with this opinion?

(Round standard error to 2 decimal places before calculating Z. Round Z to 2 decimal places before using the Normal Distribution Calculator.)

• about 0.19
• about 0.81
• about 0.62
• about 0.38

7. Research in 2018 suggests that 70% of community college students apply for financial aid, compared to 80% of all undergraduates.

We randomly sample 50 community college students. What is the probability that the sample has more than 5%?

(Round standard error to 2 decimal places before calculating Z. Round Z to 2 decimal places before using the Normal Distribution Calculator.)

• about 40%
• about 60%
• about 80%
• about 20%
• It is impossible to tell because normality conditions are not met