Answer:
y2-y1 5--6 11
-------- =. -------- = ----
x2-x1 -4 --9 5
Step-by-step explanation:
You can take out 8 so it would be
1
----
18
The confidence interval is

. This means that we can be 99% confident that the mean number of books people read lies between 9.15 and 11.85.
To find the confidence interval, we first find the z-score associated with it:
Convert 99% to a decimal: 0.99
Subtract from 1: 1-0.99=0.01
Divide by 2: 0.01/2 = 0.005
Subtract from 1: 1-0.005 = 0.995
Using a z-table (http://www.z-table.com) we see that this is associated with a z-score between 2.57 and 2.58. Since both are equally far from this value we will use 2.575.
We calculate the margin of error using

This means that the confidence interval is

The lower limit is given by 10.5-1.35 = 9.15.
The upper limit is given by 10.5+1.35 = 11.85
Yes... a half is equal to 10/20 and 11/20 is greater than 10/20 so 11/20 is greater than a half
The square root of 343 is 18.520 or 18.52 or also 18