Answer:
If our random variable of interest for this case is X="the number of teenagers between 12-17 with smartphone" we can model the variable with this distribution:

And the mean for this case would be:

And the standard deviation would be given by:

Step-by-step explanation:
If our random variable of interest for this case is X="the number of teenagers between 12-17 with smartphone" we can model the variable with this distribution:

And the mean for this case would be:

And the standard deviation would be given by:

I believe the answer to your question is three you have to be three usually always three
Answer:

Step-by-step explanation:


Well i have always gone by pemdas which is() exponits mulyiply or divide which ever comes first add subtract which ever comes first also