What is the mean of this set of data: 78, 79, 80, 80, 89, 89, 92, 93, 94, 95, 95, 95? express your answer as a decimal number rounded to the nearest tenth. 88.3 89 92 88.6

In order to the get the mean, you will have to add all of the values and then divide your answer by how many values there are. 

Let's add our values: 
78+79+80+80+89+89+92+93+94+95+95+95 = 1059. 

There are 12 values. So...:
1059/12 = 88.25. It says to round to the nearest tenth. That would be 88.3. 

the image of (6, 9) under a dilation is (4, 6). the scale factor is

b. 2/3