Complete Question
The complete question is shown on the first uploaded image
Answer:
a

b
c
The correct option is D
Step-by-step explanation:
From the question we are told that
The margin of error is 
The largest value is k = 15
The smallest value is u = 7
From the question we are told the confidence level is 95% , hence the level of significance is
=>
Generally from the normal distribution table the critical value of
is
Generally population standard deviation estimate is mathematically represented as

Here the Range is mathematically represented as

=> 
=> 
=> 
=> 
Generally 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%5Cfrac%7BZ_%7B%5Cfrac%7B%5Calpha%20%7D%7B2%7D%20%7D%20%2A%20%20%5Csigma%20%7D%7BE%7D%20%5D%20%5E2)
=> ![n = [1.96 * 2 }{0.23} ] ^2](https://tex.z-dn.net/?f=n%20%3D%20%5B1.96%20%20%2A%20%202%20%7D%7B0.23%7D%20%5D%20%5E2)
=> 
Generally to obtain a conservatively small sample size the population standard deviation estimate becomes
=> 
=> 
=> 
Generally the conservatively small sample size is mathematically evaluated as
![n = [\frac{Z_{\frac{\alpha }{2} } * \sigma }{E} ] ^2](https://tex.z-dn.net/?f=n%20%3D%20%5B%5Cfrac%7BZ_%7B%5Cfrac%7B%5Calpha%20%7D%7B2%7D%20%7D%20%2A%20%20%5Csigma%20%7D%7BE%7D%20%5D%20%5E2)
=> ![n = [1.96 * 1.333 }{0.23} ] ^2](https://tex.z-dn.net/?f=n%20%3D%20%5B1.96%20%20%2A%20%201.333%20%7D%7B0.23%7D%20%5D%20%5E2)
=>
The answer is 9.0 because 8.5 is above 5 and to the nearest tenth it would be 9.0
It is a rational number and it equals 0.5 or 1/2
-2m+4m+5=3
(-2m+4m)+(5)=3
2m+5=3
2m+5-5=3-5
2m=-2
2m/2=-2/2
m=-1