Answer: 0.670
Explanation:
Given that :
Population mean (μ) = 11.5
Sample size, n = 22
Sample mean, x = 11.7
Standard deviation, s = 1.4
The test statistic ;
Tstat = (x - μ) / (s/√n)
Tstat = (11.7 - 11.5) / (1.4/sqrt(22))
Tstat = 0.2 / 0.2984810
Tstat = 0.6700594
Tstat = 0.670 (3 decimal places )