Answer:
a) The confidence interval is 
.
Step-by-step explanation:
We have to calculate a confidence interval (CI) of a difference of proportions.
For the existing procedure, the proportion is:
For the new procedure, the proportion is:
To calculate the CI, we need to estimate the standard deviation
For a 90% CI, the z-value is 1.64.
Then, the CI is:
b is the correct answer
Step-by-step explanation:
see the step in the picture
25 degrees because 90-65=25
Answer: The string of lights will have to be 144 inches long
Step-by-step explanation:
We'll take 1.25 miles as one minute (x) and take 100 as total distance (D) while T is the time it took to reach that distance.
T = D/x
putting the values in
T = 100/1.25
T = 80
80 minutes is the answer.
