Question

For the following data values below, construct a 98% confidence interval if the sample mean is known to be 9.808 and the population standard deviation is 5.013. (Round to the nearest thousandth) (Type your answer in using parentheses! Use a comma when inputing your answers! Do not type any unnecessary spaces! List your answers in ascending order!) for example: (0.45,0.78)

Answer 1

(-19.92, 21.488)

Explanation:

given data:

98% confidence interval

Critical value of z at 98% confidence interval is t = 2.33

standard deviation = 5.031

sample mean = 9.808

z statistic to construct 98% confidence interval.

Margin of error = t * standard deviation = 2.33 * 5.013 = 11.680

98% confidence interval of mean is,

(9.808 - 11.68, 9.808 + 11.68)

(-19.92, 21.488)