Answer:
The sample required is 
Step-by-step explanation:
From the question we are told that
The standard deviation is 
The margin of error is 
Given that the confidence level is 99% then the level of significance is mathematically evaluated as



Next we will obtain the critical value
from the normal distribution table(reference math dot armstrong dot edu) , the value is

The sample size is mathematically represented as
![n = [ \frac{Z_{\frac{\alpha }{2} } * \sigma }{E} ]^2](https://tex.z-dn.net/?f=n%20%3D%20%5B%20%5Cfrac%7BZ_%7B%5Cfrac%7B%5Calpha%20%7D%7B2%7D%20%7D%20%2A%20%20%5Csigma%20%7D%7BE%7D%20%5D%5E2)
substituting values
![n = [ \frac{ 2.58 * 9 }{2} ]^2](https://tex.z-dn.net/?f=n%20%3D%20%5B%20%5Cfrac%7B%202.58%20%2A%20%209%20%7D%7B2%7D%20%5D%5E2)

ll,,Step-by-step explanation:
Answer:
A
Step-by-step explanation:
Given the 2 equations
4x + 5y = - 12 → (1)
- 2x + 3y = - 16 → (2)
Eliminate the x- term by multiplying (2) by 2 and adding the result to (1)
- 4x + 6y = - 32 → (3)
Add (1) and (3) term by term
11y = - 44 ( divide both sides by 11 )
y = - 4
Answer:
The combined score was 191
Explanation:
91 (Colin’s score) + 9 (how many more Brian had than Colin) = 100 (Brian’s score)
91 (Colin’s score) + 100 (Brian’s score) = 191 (combined score)