Question

11.90 33.67 9.72 18.30 27.10 2046 7 40 8.09 1651 14.90 15.35 5.20 29 80 14.00 14.86 14 86 7 40 8.81 30.91 19 80 Click here to yiew page 1 of the table of critical vaues or the distribution a 99% confidence rterval for the mean mot to m(Use ascending order Round to two decimal places as neoded)

Answer 1

Given that, sample size ( n ) = 20

sample mean $(\bar x)$ = 16.45 mgL

sample standard deviation ( s ) = 8.36 mgL

t-critical value at 0.01 significance level with degrees of freedom = 20 - 1 = 19 is,

to/2 = 2.861

The 99% confidence interval for population mean is,

Vn

8.36 8.36 16.45-2.861 *-< μ < 16.45 + 2.861 *

16.45-5.35 < μ < 16.45 + 5.35

11.10 < μ < 21.80

Confidence interval is, 11.10 mgL to 21.80 mgL