You Want to See If the Number of Minutes Cell $\mathrm { H } _ { 0 }$

Multiple Choice

You want to see if the number of minutes cell phone users use each month has changed from its mean of 120 minutes 2 years ago.You take a random sample of 100 cell phone users and find an average of 135 minutes used.

A) $\mathrm { H } _ { 0 }$ : ? = 135 $\mathrm { H } _ { \mathrm { A } }$ : ? > 135
B) $\mathrm { H } _ { 0 }$ : ? = 120 $\mathrm { H } _ { \mathrm { A } }$ : ? > 120
C) $\mathrm { H } _ { 0 }$ : ? = 120 $\mathrm { H } _ { \mathrm { A } }$ : ? ? 120
D) $\mathrm { H } _ { 0 }$ : ? = 120 $\mathrm { H } _ { \mathrm { A } }$ : ? < 120
E) $\mathrm { H } _ { 0 }$ : ? = 135 $\mathrm { H } _ { \mathrm { A } }$ : ? ? 135