39. A study of 2000 teens found that the number of hours they spend on social networking sites each week is normally distributed with a mean of 30 hours. The population standard deviation is 2 hours. What is the 95%
confidence interval for the mean? Evaluate and then complete the sentence. (Hint: Look at the variables given
to determine if you need equation 1 or 2 from above.) (4 pts)
The margin of error is
% meaning that we are 95% sure the actual mean is between
and
Do number 39

exa:

)

3+11

14

step-by-step explanation:

from this example, we can see that subtracting with integers is the same as adding the opposite. we can solve using a number line or by using the saying "keep, change, change" to us solve. it is important to remember that we can subtract a negative and end up with a larger number than we started with.

n=9

step-by-step explanation:

7 times a number = 7n

decreased by 13 = 7n-13

same as is =

5 times the number = 5n

increased by 5 = 5n+5

7n-13 = 5n+5

2n=18

n=9

answer: i believe the answer is e

step-by-step explanation: