Answer:
61.16667 ; (58.958, 63.375)
Step-by-step explanation:
Given the data :
72,51, 67, 68, 61, 69, 58, 56, 60, 56, 66, 61, 60, 59, 59, 54, 58, 53, 68, 63, 57, 62, 63, 64, 56, 62, 58, 67, 57, 70
Standard deviation, σ = 5.3
Sample size, n = 30
The point estimate of the population mean:
Mean, m = Σx/n
Σx = 1835 ; n = 30
m = 1835 / 30
m = 61.16667
Confidence interval :
m ± Tn-1,α/2 * σ/sqrt(n)
61.16667 ± T30-1,0.03/2 * 5.3/sqrt(30)
61.16667 ± T29,0.015 * (5.3/sqrt(30))
61.16667 ± 2.282175 * (0.9676431)
Lower bound = 61.16667 - 2.20833 = 58.95834
Upper bound = 61.16667 + 2.20833 = 63.375
(58.958, 63.375)