Question

State the conclusion based on the results of the test. According to the report, the standard deviation of monthly cell phone bills was $48.09 three years ago. A researcher suspects that the standard deviation of monthly cell phone bills is different today The null hypothesis is rejected Choose the correct answer below. O A. There is sufficient evidence to conclude that the standard deviation of monthly cell phone bills is higher than its level three years ago of $48.09. OB. There is not sufficient evidence to conclude that the standard deviation of monthly cell phone bills is different from its level three years ago of 48.09 Oc. There is sufficient evidence to conclude that the standard deviation of monthly cell phone bills is different from its level three years ago of S48.09. Click to select your answer. 133 PM #S

Answer 1

At first let's write Null and alternative hypotheses.

A researcher needed to test whether standard deviation of monthly cell phone bills is different from $48.09 i.e $\sigma$ $\neq$48.09.

Actually the claim which is to be tested is taken as alternative hypothesis and so the above is alternative hypothesis.

Null hypothesis is mathematically against alternative hypothesis and so $\sigma$ = 48.09 is Null hypothesis.

Ho : $\sigma$ = 48.09

Ha :
子o
48.09

In our problem finally the null hypothesis is rejected.

It means that the data in our problem favours the alternative hypothesis.

Conclusion:

There is sufficient evidence to concude that the standard deviation of monthly cell phone bills is different from its level 3 years ago of $48.09

Hence option C is correct.