Look in the attached file to see answer
Answer:
(a) Test statistic is -2.85 and p-value is 0.0022
(b) Reject the null hypothesis. The population mean of dissolved oxygen content is not equal to 10 mg/L
Step-by-step explanation:
H0: mu equals 10
Ha: mu not equals 10
The test is a two-tailed test because the alternate hypothesis is expressed using not equal to
(a) Test statistic (z) = (sample mean - population mean) ÷ (sd/√n) = (9.14 - 10) ÷ (2/√44) = -0.86 ÷ 0.302 = -2.85
Cumulative area of the test statistic = 0.9978
p-value = 2(1 - 0.9978) = 2(0.0022) = 0.0044
(b) The critical value using 0.02 significance level is 2.422. For a two-tailed test, the region of no rejection of the test statistic lies between -2.422 and 2.422.
Conclusion:
Reject the null hypothesis because the test statistic -2.85 falls outside the region bounded by the critical values -2.422 and 2.422.
The population mean of dissolved oxygen content is not equal to 10 mg/L
