In Juneau, Alaska, the 30 -year annual snowfall average is 86 point 7 inches with a standard deviation of 40 point 4 inches. The last four years saw an average annual snowfall of 115 point 7 inches, 62 point 9 inches, 168 point 5 inches, and 135 point 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 percent Which of the following is a conclusion that she may make?
Answer
A
The z -statistic is 4 point 6 , so the null hypothesis should be rejected.
B
The z -statistic is 1 point 8 5 , so the null hypothesis should be rejected.
C
The z -statistic is 1 point 4 4 , so the null hypothesis cannot be rejected.
D
The z -statistic is 1 point 6 8 , so the null hypothesis cannot be rejected.