Answer:

If we divide both sides by
we got:

And we can use the normal distribution table or excel to find the probabilites and we got:
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 area of a population, and for this case we know the distribution for X is given by:
Where
and 
We select a a sample of n =4 and since the distribution for X is normal then we know that the distribution for the sample mean
is given by:

And we want to find this probability:

If we divide both sides by
we got:

And we can use the normal distribution table or excel to find the probabilites and we got:

Answer:
=14
Step-by-step explanation:
I first would rearrange the problem
-220x^2 + 20x + 600x
Simplify
-220x^2 + 620x
Find the GCF of the two values
20x(11x + 13)
Hope this helps!
Answer:
81
Step-by-step explanation:
We need to know the sides of the square so 36÷4=9
Area of a square = Side x side
Area of square = 9x9=81
Answer:
7
Step-by-step explanation:
it is the 7th figure