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 three decimal places.