Answer:
And we can find this probability using the normal standard distribution table or excel and we got:

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 expected return, and for this case we know the distribution for X is given by:
Where
and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability using the normal standard distribution table or excel and we got:
Answer:
Cost of each bottle of water is $7.
Explanation:
This is the case for economies of scale. When Charles produce 1 bottle of water, it costs him $1 per bottle, when 8 bottles are produced it costs him $7. The cost per bottle of water reduces as units increases.
Answer:
Annual ordering cost=$32.142
Explanation:
Annual ordering cost = Annual demand/order quantity × ordering cost per order
Annual demand = 15 × 12 = 180 units
Kindly note that there are 12 months in year.
Annual Ordering cost = 180/28 × $5= $32.142
Annual ordering cost=$32.142