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:

Answer: A: 1524 miles B: Average is 508 mph
Step-by-step explanation: Add the miles on the picture to get the total amount of miles traveled (1524) and then divide by 3 hours to get 508 mph.
Hope this helped!
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together = add
add the fractions
3 7/10 + 5 9/10
add the whole numbers first
3+5=8
add the fractions
7/10+9/10= 16/10
8 16/10
reduce 16/10 divide by 2
16/2= 8
10/2= 5
8 8/5
whole number changes to 9
8-5=3
denominator stays the same
9 3/5
Answer:
9 3/5
Answer: 5
Step by Step Explanation: