Answer:
μ−2σ = 1,089.26
μ+2σ = 1,097.62
Step-by-step explanation:
The standard deviation of a sample of size 'n' and proportion 'p' is:

If n=1139 and p =0.96, the standard deviation is:

The minimum and maximum usual values are:


Answer:
a. 1 1/8 b. 8/9
Step-by-step explanation:
You can set this up as a proportion to solve. For part a. we know that 2/3 of the road is 3/4 mile long. 2/3 + 1/3 = the whole road, so we need how many miles of the road is 1/3 its length. Set up the proportion like this:

Cross multiplying gives you:

The 3's on the right cancel out nicely, leaving you with

To solve for x, multiply both sides by 3/2:
gives you

That means that the road is still missing 3/8 of a mile til it's finished. The length of the road is found by adding the 3/4 to the 3/8:

So the road is a total of 1 1/8 miles long.
For b. we need to find out how much of 1 1/8 is 1 mile:
1 mile = x * 9/8 and
x = 8/9. When 1 mile of the road is completed, that is 8/9 of the total length of the road completed.
Answer:

Step-by-step explanation:
<u>Step 1: Set x to -2
</u>




Answer: 
The first step to dividing fractions is to find the reciprocal (reverse the numerator and denominator) of the second fraction. Next, multiply the two numerators. Then, multiply the two denominators. Finally, simplify the fractions if needed.