the average (arithmetic mean) of 4 numbers is greater than 7 and less than 11.What is one possible number that could be the sum of these 4 numbers?
2007-04-15 15:23:13 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Let a, b, c, and d be the numbers. The arithmetic mean would be
(1/4)(a + b + c + d)
This is between 7 and 11.
7 < (1/4)(a + b + c + d) < 11
We can now solve this inequality. Multiply 4 to get rid of the (1/4) to get
28 < a + b + c + d < 44
One possible number that could be the sum of these 4 numbers is obtained by choosing any number between 28 and 44.
2007-04-15 15:29:21 · answer #1 · answered by Puggy 7 · 0⤊ 0⤋
Let's say S is the sum of the 4 numbers. Then the average is S/4, right. So 7 < S/4 < 11
multiply the inequality by 4
28 < S < 44. Therefore S can be any number between 28 and 44, not inclusive
2007-04-15 22:40:41 · answer #2 · answered by Kathleen K 7 · 0⤊ 0⤋
Let 'm' stand for the mean and 's' stand for the sum.
m = s/4
s = 4m
so the sum has to be in between 4*7 and 4*11, or between 28 and 44. Any number will do (excluding 28 and 44 themselves).
2007-04-15 22:29:05 · answer #3 · answered by J 2 · 0⤊ 0⤋
They are telling you there are 4 numbers and their average is over 7 and under 11. This means that the least the total could be is 28 (4x7) and the most it could be is 44 (4x11).
So the answer is any number from 29 to 43.
2007-04-15 22:32:52 · answer #4 · answered by ignoramus 7 · 0⤊ 0⤋
7+7+7+8 makes ave > 7
11+11+11+10 makes ave <11.
So sum can be anywhere from 29 to 43
2007-04-15 22:29:27 · answer #5 · answered by TadaceAce 3 · 0⤊ 0⤋
um 28, 32, 36 and 40. and anything in between
2007-04-15 22:27:52 · answer #6 · answered by Anonymous · 0⤊ 0⤋