Answer:
a) 
With:


b) 

c) 

d) 


Step-by-step explanation:
For this case we know the following propoertis for the random variable X

We select a sample size of n = 81
Part a
Since the sample size is large enough we can use the central limit distribution and the distribution for the sampel mean on this case would be:

With:


Part b
We want this probability:

We can use the z score formula given by:

And if we find the z score for 89 we got:


Part c

We can use the z score formula given by:

And if we find the z score for 75.65 we got:


Part d
We want this probability:

We find the z scores:



Answer: Coeffcient is 17
Explaination:-
Given expression is :
17xy³z¹²
To find the coefficient of given expression
In mathematics, a coefficient is a multiplicative factor in some term of a polynomial, a series, or any expression; it is usually a number, but may be any expression.
For example : In 2x⁵
Coeffcient is 2
Now come to the question:
Coeffcient is 17.
Answer:
x = 13
Step-by-step explanation:
Now since the lines are parrarel, the intersection points are alternate to each other. Therefore, A = B.
Solve:
8x + 2 = 14x - 76
2 + 76 = 6x
78 = 6x
x = 13
Answer:
169,000 people
Step-by-step explanation:
increase from 2010-2015:
168000/100 = 1680 = 1%
1680 x 7 = 11,760 people
population at 2015 = 168000+11760 = 179,760
decrease from 2015-2020:
179760/100 = 1797.6 = 1%
1797.6 x 6 = 10,785.6 people
population at 2020 = 179760-10787.6 = 168,974.4 people
rounded to the nearest 100 = 169,000 people