if the numbers 9, 10, and 15 occur with the frequencies 6, 4, and 10, respectively, what is the mean?

Question

1) 11.3
2) 12.2
3) 131
4) 8.9
5) 7.1

Answer 1

I assume this means you have 6 9's, 4 10's and 10 15's. That's 54, 40 and 150. And it's 20 numbers. The total is 244. The mean is 244/20 = 12.2. That would make it answer 2).

Answer 2

The answer is #2 (12.2).
To get a mean, yuo add up all the numbers that occur, and divide by the total number of occurrences.
So you have 6 occurrences of the number 9(multiply to get 9*6=54).
PLUS
4 occurrences of the number 10 (10*4=40).
PLUS
10 occurrences of the number 15 (15*10=150).

The sum of these (54+40+150) is 244. Now you divide by the total number of occurrences (6+4+10 = 20).

244/20 = 12.2

Answer 3

number3