Question

1. On March 28 at 1:30 pm, I randomly selected 10 states and found the number of coronavirus cases in each of them. This gave me an average of 939 cases with a standard deviation of 1543. Assume the number of cases in each state is normally distributed. Create a 90% confidence interval for the actual number of coronavirus cases in each state.

2. On March 28 at 1:30 pm, the actual average number of cases in a U.S. state was 2102. Does this value fall in the interval you found in question 1. Discuss why or why not, and the reason you found the result you did.

3. Using the scenario from question 1, how many states would need to be selected to be 90% confident that the sample mean number of cases would be within 500 of the actual mean?

Answer 1

A) df = 10 - 1 = 9

At 90% confidence level, the critical value is t0.05, 9 = 1.833

The 90% confidence interval is

No, 2102 doesn't lie in the confidence interval.

Margin of error = 500

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