Question

6. The average depth of the Hudson Bay is 305 feet. Climatologists were interested in seeing if global climate change was affecting the water level. 55 measurements over a period of randomly selected weeks yielded a sample mean of 306.2 feet. The population variance is known to be 3.6 feet. Can it be concluded at 0.05 level of significance that the average depth has increased ? Use the following steps to answer this question:

i. State H0 & HA & indicate if it is left-tail or a right-tail or a two-tail test

ii. Find the table z value

iii. Find the calculated z-value

iv. Explain why you would or would not reject H0

Answer 1

solution : 6 Ho: M=305 D is Right tailed test Ha: es > 305 This Z-critical ri) Allia za 1.6 mi) z-value 306.8-305 X-M olm 3.6 155 et Test stahistica 4.69 s 1.64 iv sima, Test statistic so, Reject Ho blox