Question

The Juniors and Seniors reported their scores on a standardized math test. The teacher displayed their scores on dot plots.

What is the MAD for the Junior and Senior scores?

0.7
29.3
14.3 and 15
14 and 14.4

Answer 1

14 and 14.4

Explanation:

✍️MAD for Juniors:

✔️Write out the individual scores represented in the dot plot:

505, 505, 510, 515, 525, 530, 530, 540, 550, 550

✔️Find the mean of the data set =
`(505 + 505 + 510 + 515 + 525 + 530 + 530 + 540 + 550 + 550)/(10) = (5,260)/(10) = 526`

✔️Find |data value - mean|:

|505 - 526| = 21

|505 - 526| = 21

|510 - 526| = 16

|515 - 526| = 11

|525 - 526| = 1

|530 - 526| = 4

|530 - 526| = 4

|540 - 526| = 14

|550 - 526| = 24

|550 - 526| = 24

✔️Find the sum of |data value - mean| and divide by 10:

`(21 + 21 + 16 + 11 + 1 + 4 + 4 + 14 + 24 + 24)/(10) = (140)/(10) = 14`

✅M.A.D = 14

The same steps would be taken to find the MAD for Seniors.

✍️MAD for Seniors:

✔️Write out the individual scores represented in the dot plot:

535, 535, 535, 550, 550, 550, 560, 575, 575, 580

✔️Find the mean of the data set = sum of all values in the data set ÷ 10 = 554.5

✔️Find the M.A.D by dividing the sum of |data value - mean| by 10:

`(144)/(10) = 14.4`

✅M.A.D = 14.4