Our environment is very sensitive to the amount of ozone in the upper atmosphere. The level of ozone normally found is 6.0 parts/million (ppm). A researcher believes that the current ozone level is not at a normal level. The mean of 13 samples is 5.6 ppm with a variance of 0.49. 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 two decimal places. Answer Tables Keypad How to enter your answer (opens in new window) Keyboard Shortcuts