Construct a 95% confidence interval for the population mean. 5. Airfare A random sample of airfare prices (in dollars) for a one-way ticket airfare between two cities MN. Key: 21|1=211

21 | 1 2
22 | 1 1 1 2 3 5 7 8
23 | 2 3 4 7 7 8 9 9
24 | 2 3 4 8 8
25 | 1 2 6 6 6 6 8 9

1 answer

95% = mean ± 2 SD

Find the mean first = sum of scores/number of scores

Subtract each of the scores from the mean and square each difference. Find the sum of these squares. Divide that by the number of scores to get variance.

Standard deviation = square root of variance

I'll let you do the calculations.