You must estimate the mean temperature (in degrees Fahrenheit) with the following sample temperatures:

Question

13.7

24.2

22.5

5.7

6

15.3

21.8

Find the 99% confidence interval. Enter your answer as an open-interval (i.e., parentheses) accurate to two decimal places (because the sample data are reported accurate to one decimal place).

99% C.I. =

Answer should be obtained without any preliminary rounding.

Answer 1

You will first need to calculate the mean and standard deviation of the sample. You can calculate by hand or use excel or Ti-84 among other technology

Once you calculate the sample mean and standard deviation, the CI is found by:

sample mean +/- Z₉₉ (sample std.dev/√n)

For reference, Z values for commonly used intervals:

90% CI: Z=1.645

95% CI: Z= 1.96

99% CI: Z= 2.575