Question

A compound found in drinking water is said to be harmless if its recoverable amount in the drinking water was 25ppm (or less). An independent organization investigate a source of drinking water and believe that the source does not comply with the standards.

a) Specify an error type I that might be done by this organization and effects of the action to be taken because doing the error.

b) Specify an error type II which may be done by this organization and action will be taken because doing the error.

Answer 1

Null Hypothesis(H0): 25 ppm (the source complies with the standards).

Alternative Hypothesis(H1): > 25 ppm (the source does not comply with the standards).

a)

Type I error is the rejection of a true null hypothesis. So, in this case, type I error is rejecting that the source complies with the standards when in fact the source complies with the standards.

Because of this error, the organization concludes that the source does not comply with the standards and so, it considers harmless drinking water as not harmless(or harmful).

b)

Type II error is failing to reject a false null hypothesis. In this case, type II error means failing to reject that the source complies with the standards when in fact the source does not comply with the standards.

Because of this error, the organization concludes that the source complies with the standards and so, it considers harmful drinking water as harmless so that the people continue to drink that harmful water which is dangerous.

Thus, in this case, type II error is more serious than type I error.