1) A new hand-eye coordination test was designed so that the average score in the population was 1,000 with a population standard deviation of 200. For this question, assume a sample size of 100 people randomly draw from the relevant population. Show the proportion (or percent) and relevant z-scores.

A) What percent of such samples would we expect to have an average score over 1,050?

B) What percent of such samples would we expect to have an average score under 970?

C) What percent of such samples would we expect to have an average score under 1,040?

D) What percent of such samples would we expect to have an average score between 960 and 1,020?

For problems 2-5, you are asked to calculate a confidence interval. Your calculation should include all intermediate values. Intermediate values include:

For confidence intervals based on

• XX-: z,XX-

For confidence interval based on

• sXsX-: df, t,sXsX-

For confidence intervals for proportions: z and s_p

2) In a sample of 50 IT help desk workers, the average number of tickets closed an hour was 4 (s=5).

Calculate a 95% confidence interval for the average tickets closed an hour. Be sure to show all relevant intermediate values.

Interpret the meaning of this confidence interval.

3) In a sample of college students (N=36), the average number of people talked to a day was 40, with a standard deviation of 12.

Calculate a 95% confidence interval for people talked to. Be sure to show all relevant intermediate values.

Interpret the meaning of this confidence interval.

4) A recent Gallup poll of American adults found that 65% of Americans believe that the government is doing too little to address the effects of climate change (N=10,957).

Calculate a 99% confidence interval for this proportion. Be sure to show all relevant intermediate values.

Interpret the meaning of this confidence interval.

5)For the second problem set, you worked with data on the times that people were hospitalized. In this sample of 3,578 teenagers, the average times hospitalized was 0.067 (s=0.50).

Calculate a 95% confidence interval for times hospitalized. Be sure to show all relevant intermediate values.

Interpret the meaning of this confidence interval.