Answer:
Percentage increase = 269%
Step-by-step explanation:
Price of a DVD last week = $2.87
Price of the same DVD this week = $10.59
Increase in the price of DVD between last week and this week = 10.59 - 2.87
= $7.72
Therefore, percentage increase in the price of DVD = 
= 
= 268.99
= 269%
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
The answer would be B. (228-89) because you are trying to find the difference.
The answer is C .12/15 since you can divide A,B,D and get 2/3 but you cannot with C
3x=2
x= 2/3
slope is undefined. there is no y intercept
