Assume that the national average daily water usage in Canada for 2019 was 492 L per person. Suppose some analysts believe that more water is being used now and want to determine whether this is so. They randomly select a sample of Canadians and carefully keep track of the water used by each sample member for a day, then analyze the results by using a statistical computer software package. The output is given here. Assume α = 0.05. How many people were sampled? What was the sample mean? Was this a one- or two-tailed test? What was the result of the study? What decision could be made about the null hypothesis from these results?

Transcribed Image Text:

One-Sample z Test of μ = 492 vs. > 492 The assumed standard deviation = 101.72 n 40 Mean SE Mean 529.44 17.508 95% Lower Bound 500.644 Z 2.14 Р 0.016