# Thread: Hypothesis testing.

1. ## Hypothesis testing.

The maximum acceptable level of a certain toxic chemical in vegetables has been set at 0.4 parts per million (ppm). A consumer health group measured the level of the chemical in a random sample of tomatoes obtained from one producer. The levels, in ppm, are shown below.

0.31 0.47 0.19 0.72 0.56 0.91 0.29 0.83 0.49 0.28
0.31 0.46 0.25 0.34 0.17 0.58 0.19 0.26 0.47 0.81

At the 5% significance level, do the data provide sufficient evidence to conclude that the mean level of the chemical in tomatoes from this producer is greater than the recommended level of 0.4 ppm? Assume that the population standard deviation of levels of the chemical in these tomatoes is 0.21 ppm.

2. Originally Posted by KnicksFan
The maximum acceptable level of a certain toxic chemical in vegetables has been set at 0.4 parts per million (ppm). A consumer health group measured the level of the chemical in a random sample of tomatoes obtained from one producer. The levels, in ppm, are shown below.

0.31 0.47 0.19 0.72 0.56 0.91 0.29 0.83 0.49 0.28
0.31 0.46 0.25 0.34 0.17 0.58 0.19 0.26 0.47 0.81

At the 5% significance level, do the data provide sufficient evidence to conclude that the mean level of the chemical in tomatoes from this producer is greater than the recommended level of 0.4 ppm? Assume that the population standard deviation of levels of the chemical in these tomatoes is 0.21 ppm.
This is a standard type of problem, similar to examples that will be in your classnotes and textbook. What have you tried and where do you get stuck?