A teacher interested in determining the effect of a new computer program on learning to read conducted a study. One hundred students were randomly assigned to one of tu groups. The first group used the computer program while the second group did not. Both groups were tested to determine how much their reading levels improved. The results for the two groups were compared. What kind of study is this?

This is an experiment because a treatment was applied to a group.

Step-by-step explanation:

There are two groups, The first group used the computer program while the second group did not therefore this is an experiment. An experiment involves changing an independent variable to see how it affects a dependent variable. The dependent variable in this case  determining the effect of a new computer program on learning while the independent variables was testing with the computer program and not testing with the program.

step-by-step explanation:

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