In Juneau, Alaska, the 30-year annual snowfall average is 86.7 inches with a standard deviation of 40.4 inches. The last four years saw an average annual snowfall of 115.7 inches, 62.9 inches, 168.5 inches, and 135.7 inches. Hia performs a hypothesis test on this data to determine if the next 30-year norm will have a different average if the trend from the last four years continues. She uses a significance level of 5%. Which of the following is a conclusion that she may make?

Question

In Juneau, Alaska, the 30-year annual snowfall  average is 86.7 inches with a standard deviation of 40.4 inches. The  last four years saw an average annual snowfall of 115.7 inches, 62.9 inches, 168.5 inches, and 135.7 inches. Hia performs a hypothesis test on this data to determine if the next 30-year norm will have a different average if the trend from the last four years continues. She uses a significance level of 5%. Which of the following is a conclusion that she may make?

jodecci · Answer

The z-statistic is 1.44, so the null hypothesis cannot be rejected.
The z-statistic is 1.68, so the null hypothesis cannot be rejected.
The z-statistic is 1.85, so the null hypothesis should be rejected.
The z-statistic is 4.6, so the null hypothesis should be rejected.