Question

To be acceptable as a source of drinking water, the mean nitrogen content must be no more than 0.07ppm. A Chemist wants to find out whether the mean nitrogen content at the Wonder lake exceed the acceptable limit for drinking water. The water was sampled randomly from 24 locations in the lake. The sample yielded an average of 0.08 ppm and a standard deviation of 0.032 ppm. Assume normality for the nitrogen content.

(a) State the hypotheses.

(b) Calculate the test statistic, state the degrees of freedom, and give an interval for the p-value using the appropriate table in text book.

(c) Would you reject H0 or fail to reject H0 at 5% level of significance.

(d) What do you conclude about the water at the Wonder lake?

(e) What type of error are you subject to for making your decision in part (c)?

(f) How would you reduce the rate of this error?

Answer 1