Answer: 8359
Step-by-step explanation:
The formula for sample size needed for interval estimate of population proportion :-

Given : The significance level : 
Critical value : 
Previous estimate of proportion : 
Margin of error : 
Now, the required sample size will be :-

Hence, the required sample size = 8359
It would just be the tot foot time the cost
7.5 X 0.50 = $3.75
Factor out the common term 4
-4(2x - y) = 24
Divide both sides by -4
2x-y= - 24/4
Simplify24/4 to 6
2x -y = -6
Subtract 2x from both sides
-y = -6 - 2x
Multiply both sides by -1
y = 6 + 2x