you decide to halve the time you spend in the shower each day and to turn off the water while you’re brushing your teeth and washing your face at the sink. Evaluate the effect that these actions might have onto different aspects of the water cycle if every person in your neighborhood also performed them.

The difference of sample means of two populations is 55.4, and the standard deviation of the difference of sample means is 28.1. which statement is true if we are testing the null hypothesis at the 95% confidence level? a. the difference of the two means is significant, so the null hypothesis must be rejected. b. the difference of the two means is significant, so the null hypothesis must be accepted. c. the difference of the two means is not significant, so the null hypothesis must be rejected. d. the difference of the two means is not significant, so the null hypothesis must be accepted.