B is the right answer to this question
Answer:
its righties b
Step-by-step explanation:
Answer:
The sample size is 
Step-by-step explanation:
From the question we are told that
The sample standard deviation is 
The mean difference of the two groups is 
The standard error is 
=> 
Let assume that the confidence level is 95% hence the level of significance is

=> 
So the critical value of
obtained from the normal distribution table is

Generally the margin of error is mathematically evaluated as

Generally the sample size is mathematically represented as
![n =[ \frac{Z_{\frac{\alpha }{2} * s^2}}{E}]^2](https://tex.z-dn.net/?f=n%20%3D%5B%20%5Cfrac%7BZ_%7B%5Cfrac%7B%5Calpha%20%7D%7B2%7D%20%20%2A%20s%5E2%7D%7D%7BE%7D%5D%5E2)
=> ![n = [\frac{1.96 * 1.5}{0.49} ]^2](https://tex.z-dn.net/?f=n%20%20%3D%20%5B%5Cfrac%7B1.96%20%2A%201.5%7D%7B0.49%7D%20%5D%5E2)
=> 
Answer:
B. a = 5
Step-by-step explanation:
3(a - 4) + 1 = 9 - a
Distribute the 3 into the parenthesis.
3a - 12 + 1 = 9 - a
Add -12 and 1.
3a - 11 = 9 - a
Add a to both sides.
4a - 11 = 9
Add 11 to both sides.
4a = 20
Divide both sides by 4.
a = 5.
Proof:
3(a - 4) + 1 = 9 - a
Substitute variable.
3(5 - 4) + 1 = 9 - 5
Subtract inside parenthesis.
3(1) + 1 = 9 - 5
Multiply 3 and 1.
3 + 1 = 9 - 5
Add 3 and 1.
4 = 9 - 5
Subtract 5 from 9.
4 = 4.