According to the CTIA-The Wireless Association, the mean monthly revenue per cellphone was $48.79 in 2014. A researcher suspects the mean monthly revenue per cell phone is different today. (a). Write...

According to the CTIA-The Wireless Association, the mean monthly revenue per cellphone was $48.79 in 2014. A researcher suspects the mean monthly revenue per cell phone is different today.

(a). Write down the null and alternative hypotheses. Determine whether the hypotheses test is left-tailed, right-tailed, or two-tailed.

(d) Based on the results of the sample data, the null hypothesis is rejected. State the conclusions based on the results of the test.