A manufacturer of a chemical used in glue, attempting to control the amount of a hazardous chemical its workers are exposed to, has given instructions to halt production if the mean amount in the air exceeds 3.0ppm. A random sample of 50 air specimens produced the following statistics: sample mean = 3.1 ppm , sample standard deviation = 0.5 ppm. Calculate the appropriate test statistic to test the hypotheses.
A. 0.20
B. -0.20
C. 10.00
D. 1.41
E. -1.41