Question

How many different approaches are there to the construction of confidence intervals for the mean?

Group of answer choices

3

1

4

2

Assume a sample of 25 students, and we want to estimate the number of hours spent per week studying during a typical semester. We find the mean of our sample to be 12 and the standard deviation to be 3. Construct a 95% confidence interval for an estimate of the mean.

10.76 to 13.24

9 to 15

9.94 to 14.06

1.76 to 4.24

Assume the following: = 50, σ = 8, n = 400. Calculate a 99% confidence interval.

49.2 to 50.8

47.94 to 52.06

48.97 to 51.03

49.6 to 50.4

Assume the following: = 50, σ = 8, n = 100. Calculate a 95% confidence interval.

46.86 to 53.14

42 to 58

48.43 to 51.57

49.2 to 50.8

Group of A statistician wants to determine how many people would approve of a new countywide sales tax. He surveys 400 people and finds that 55% are in favor of the tax. Construct a 95% confidence interval for the proportion.

I have no idea and am completely lost

53.04% to 56.96%

50.12% to 59.87%

54.98% to 55.02%

What would the interval or range be for a proportion of 45% with a margin of error of 5%?

40% to 50%

40% to 45%

45% to 50%

42.5% to 47.5%

Answer 1