Sagot :
a. 18
b. (17 . 27, 18 . 73)
Step-by-step explanation:
[tex]n = 25 \: \: \: \: x = 18 \: \: \: s = 1.3 \\ \alpha = 1 - 99\% = 1\% \: \: \frac{ \alpha }{2} = 0.5\% \\ t \frac{ \alpha }{2} (n - 1) \: t \: 0.5\%(24) = 2.7969[/tex]
a. Point estimate = x = 18
b.
[tex]x + t \frac{ \alpha }{2} (n - 1). \: s \sqrt[n]{n} \\ = 18 + 2.7969 \times 1.3 \div \sqrt[n]{25} \\ = 18 + 2.7969 \times 1.3 \div 5 \\ \: \: \: \: \: \: \: \: \: \: \: = 18 + 0.727194 \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ = (17.27 \: \: 18.73)[/tex]