Question

Betty tabulated the miles-per-gallon values for her car as 26.5, 28, 30.2, 29.6, 32.3, and 24.7. The sample standard deviation is 2.728. The driver’s manual for Betty’s car lists the mpg for her car as 25. t equals fraction numerator x with bar on top minus mu over denominator begin display style beveled fraction numerator s over denominator square root of n end fraction end style end fraction The t test statistic for a two-sided test would be __________.

Answer 1

3.188

Explanation:

Given that :

Sample data: 26.5, 28, 30.2, 29.6, 32.3, 24.7

Sample standard deviation (s) = 2.728

Mean (mu) = 25

Tstatistic formula :

(x - mu) / (s/sqrt(n))

n = sample size = 6 ; s = 2.728 ; mu = 25

Sample mean (x) = (26.5 + 28 + 30.2 + 29.6 + 32.3 + 24.7) / 6

Sample mean (x) = 171.3 / 6 = 28.55

Tstatistic = (28.55 - 25) / (2.728 / sqrt(6))

Tstatistic = 3.55 / 1.1137013

Tstatistic = 3.1875692