Answer:
Where
and
We select a sample of n=16 and we are interested on the distribution of
, since the distribution for X is normal then we can conclude that the distribution for
is also normal and given by:

Because by definition:



And for this case we have this:


Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the IQ scores of a population, and for this case we know the distribution for X is given by:
Where
and
We select a sample of n=16 and we are interested on the distribution of
, since the distribution for X is normal then we can conclude that the distribution for
is also normal and given by:

Because by definition:



And for this case we have this:


24 ice-cream cartons in a box, and you have 13 boxes. Therefore, you do 24 times 13.
24 x 10 = 240.
3 x 4 = 12
(3 x 2 = 6) x 10 = 60.
240
+60
+12
=312
Tom has 312 cartons of ice-cream