Answer:
C. 5 weeks.
Step-by-step explanation:
In this question we have a random variable that is equal to the sum of two normal-distributed random variables.
If we have two random variables X and Y, both normally distributed, the sum will have this properties:

To calculate the expected weeks that the donation exceeds $120, first we can calculate the probability of S>120:

The expected weeks can be calculated as the product of the number of weeks in the year (52) and this probability:

The nearest answer is C. 5 weeks.
Answer: a) (1008.34,1019.658) b) (1009.24,1018.76)
Step-by-step explanation:
Since we have given that
n = 75
mean = 1014 hours
Standard deviation = 25 hours
At 95% two sided , z = 1.96
So, confidence interval would be

(b) Construct a 95% lower confidence bound on the mean life.
z = 1.65
So, confidence interval would be

Hence, a) (1008.34,1019.658) b) (1009.24,1018.76)
Answer:
YES
NO
NO
Step-by-step explanation:
The given polynomial is: 
(x - a) is a factor of a polynomial iff x = a is a solution to the polynomial.
To check if (x - 5) is a factor of the polynomial f(x), we substitute x = 5 and check if it satisfies the equation.
∴ f(5) = 5³ + 4(5)² - 25(5) - 100
= 125 + 100 - 125 - 100
= 225 - 225
= 0
We see, x = 5 satisfies f(x). So, (x - 5) is a factor to the polynomial.
Now, to check (x + 2) is a factor.
i.e., to check x = - 2 satisfies f(x) or not.
f(-2) = (-2)³ + 4(-2)² - 25(-2) - 100
= -8 + 16 + 50 - 100
= -108 + 66
≠ 0
Therefore, (x + 2) is not a factor of f(x).
To check (x - 4) is a factor.
∴ f(4) = 4³ + 4(4)² - 25(4) - 100
= 64 + 64 - 100 - 100
= 128 - 200
≠ 0
Therefore, (x - 4) is not a factor of f(x).
<span>5^2 + 10^2 = 125
c^2 = 125
c = √125 = √(25•5) = = 5√5</span>