Question

Our environment is very sensitive to the amount of ozone in the upper atmosphere. The level of ozone normally found is 4.1 parts/million (ppm). A researcher believes that the current ozone level is not at a normal level. The mean of 23 samples is 4.5 ppm with a variance of 1.44. Assume the population is normally distributed. A level of significance of 0.1 will be used. Find the value of the test statistic. Round your answer to three decimal places.

Answer 1

s² = 1.44

s = = 1.2

The test statistic t = ()/(s/)

                            = (4.5 - 4.1)/(1.2/)

                            = 1.599