The lifetimes of light bulbs of a particular type are normally distributed with a mean of 210 hours 14) and a standard deviation of 5 hours. what percentage of the bulbs have lifetimes that lie within 1 standard deviation to either side of the mean

7.  Answer= $26.28

So we know that 5 cans = $10.95

Then you can find what 1 can equals using this equation:  

Price / can = price per can              10.95/5=2.19

Now you multiply that by twelve ( think of it like 1 can=$2.19 )

2.19*12=26.28

8. Answer= 119/22

So we know that 11 in. length = 8.5 in. width and that the length of the new paper is 7 in.

Now you divide 11/7 (because 11 divided by 7 is 11/7) by 8.5 because your scaling down. (Or you can multiply it by 7/11

8.5*7/11= 119/22

9. Answer = 7.5

In the triangle you have sides with lengths of 8, 8, and 5.

Now you divide 12 by 8 and then multiply that quotient by 5.

12/8 * 5 = 7.5

Hope this helps :)