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:

Answer:
CD
Step-by-step explanation:
if B comes after A and you put them together that makes AB so do the same for CD CD is the answer
Answer:
72
Step-by-step explanation:
The pythagorean theorem states that in a right triangle A^2 + B^2 = C^2 where A and B are the two smaller sides and C is the hypotenuse.
Because of this, in this triangle 30^2 + B^2 = 78^2
Which means B^2 = 5184
And B = 72