David measured the heights of 10 classmates. He found the mean of their heights to be 54.8 inches. He then added in his own height and found the mean again. With David’s height, the mean was 55 inches. What is David’s height?

d

step-by-step explanation:

if you are saying purchasing 3 social media ads and one newspaper ad counts as one purchase then there are:

6 purchases

if you are asking how many of each then:

18 social media ads

6 newspaper ads

you didn't give me the choices, so i will just give you the graph so you can look at your choices and choose the right one.