Q + d = 16....q = 16 - d
0.25q + 0.10d = 3.10
0.25(16 - d) + 0.10d = 3.10
4 - 0.25d + 0.10d = 3.10
-0.25d + 0.10d = 3.10 - 4
-0.15d = -0.90
d = -0.90/-0.15
d = 6...dimes
q + d = 16
q + 6 = 16
q = 16 - 6
q = 10...quarters
so there are (10 - 6) = 4 more quarters then dimes
Answer:
And using the normal standard table or excel we find the probability:

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 avergae number of weeks an individual is unemployed of a population, and for this case we know the distribution for X is given by:
Where
and
Since the distribution for X is normal then, the distribution for the sample mean
is given by:
We select a sample of n =50 people. And we want to find the following probability
And using the normal standard table or excel we find the probability:

A tshirt and jeans, or shorts