Question

THREE QUESTIONS 21POINTS HELP!!!

8. Six boys have heights of 1.53 m, 1.49 m, 1-60 m, 1.65 m, 1.90 m and 1.43 m. (a) Find the mean height of the six boys. (b) Find the mean height of the remaining five boys when the shortest boy leaves.

9. In a maths test the marks for the boys were 9, 7, 8, 7, 5 and the marks for the girls were 6, 3, 9, 8, 2, 2. (a) Find the mean mark for the boys. (b) Find the mean mark for the girls. (c) Find the mean mark for the whole class.

10. Five different drinks have an average (mean) price of £1.50. When a sixth drink is added the new average price is £1.60. How much did the sixth drink cost?​

Answer 1

I'll do problem 8 to get you started.

Part (a)

To find the mean, we first add up the values

1.53+1.49+1.60+1.65+1.90+1.43 = 9.6

Then divide over 6 since this is the number of values in the set.

9.6/6 = 1.6

Answer: 1.6 meters

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Part (b)

The shortest boy is 1.43 meters tall. If he leaves the group, then we have these heights leftover

1.53, 1.49, 1.60, 1.65, 1.90

Adding them up gets us

1.53+1.49+1.60+1.65+1.90 = 8.17

Then divide by 5

8.17/5 = 1.634

Answer: 1.634 meters