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:
q = 20
Step-by-step explanation:
1/5q = 4
q = 20
Answer:
160 jars
Step-by-step explanation:
To find how many jars were used, we just need to divide the amount of stuff by the amount of stuff a jar can hold.
400 (the amount of peanut number in pounds) / 2.5 (the amount of peanut butter each jar can hold) = 160.
So, 160 jars were used to package the 400 pounds of peanut butter.
Answer:
x = 177/8
Step-by-step explanation:
First, we must get rid of the fraction by multiplying 8 by both sides.
8 · 1/8(8x + 15) = 24 · 8
1(8x + 15) = 192
8x + 15 = 192
Then we simplify. First subtract 15 from both sides.
8x + 15 - 15 = 192 - 15
8x = 177
Then divide 8 from both sides.
8x/8 = 177/8
x = 177/8
1/2 + 4x = 5x - 5/6
1/2 = x - 5/6
3/6 = x - 5/6
x = 8/6