Skip to content
Home › Grade 7 Math › Grade 7 Tests › Comparing Two Populations Test Answer Key with Scoring – Grade 7

Comparing Two Populations Test Answer Key with Scoring – Grade 7

← Back to the Comparing Two Populations test

Last updated: October 22, 2026 · Written by the Math Made Easy math teachers

Grade 7 Math Test Answer Keys – Mathbot, the Math Made Easy robot coach, with free printable test answer keys for Grade 7
Looking for a comparing two populations test answer key? Then this answer key gives the solutions and the scoring guide of the Grade 7 test on Comparing Two Data Sets with Variability. The answer key shows every calculation and a scoring guide. Award partial credit when a student lists correct distances from the mean but makes a small addition error, and check that units are included where given.

Standards: 7.SP.B.3, 7.SP.B.4 · Level: Grade 7

Question 1 Mean and MAD (2 points)

  1. Sum 80, so the mean is 80 ÷ 5 = 16 books.
  2. Distances: 2, 2, 4, 0, 4. Sum 12. MAD = 12 ÷ 5 = 2.4 books.

Scoring: 1 point for each part.

Question 2 Two dot plots (3 points)

  1. Team X: 50 ÷ 10 = 5. Team Y: 70 ÷ 10 = 7.
  2. Distances for X: 2, 1, 1, 0, 0, 0, 0, 1, 1, 2. Sum 8. MAD = 8 ÷ 10 = 0.8.
  3. Difference: 7 − 5 = 2. 2 ÷ 0.8 = 2.5 MADs.

Scoring: 1 point for each part.

Question 3 Two box plots (3 points)

  1. Class A: 26. Class B: 38.
  2. Class A: 32 − 20 = 12. Class B: 44 − 32 = 12.
  3. 38 − 26 = 12, and 12 ÷ 12 = 1 IQR.

Scoring: 1 point for each part.

Question 4 Quartiles from a list (2 points)

The median is the middle (4th) value: 12.

Lower half: 4, 7, 9 gives Q1 = 7. Upper half: 15, 18, 22 gives Q3 = 18. IQR = 18 − 7 = 11.

Scoring: 1 point for the median, 1 point for the IQR.

Question 5 Cookie weights (3 points)

  1. A: 180 ÷ 6 = 30 g. B: 210 ÷ 6 = 35 g.
  2. A: distances 2, 0, 1, 1, 0, 2 sum 6, MAD = 1 g. B: distances 2, 0, 1, 1, 0, 2 sum 6, MAD = 1 g.
  3. 35 − 30 = 5, and 5 ÷ 1 = 5 MADs.

Scoring: 1 point for each part.

Question 6 Same median, different spread (2 points)

Set 1 is more consistent. Its middle half of values is within 4 units, while the middle half of Set 2 is spread over 20 units.

Set 1

Scoring: 1 point for choosing Set 1, 1 point for the reason using IQR.

Question 7 Draw a box plot (3 points)

Draw whiskers to 5 and 22, a box from 9 to 16, and a line in the box at 12. Range: 22 − 5 = 17. IQR: 16 − 9 = 7.

range 17; IQR 7

Scoring: 1 point for a correct box plot, 1 point for the range, 1 point for the IQR.

024681012141618202224Data setValue
The finished box plot.

Question 8 Two teams (2 points)

  1. 72 − 62 = 10, and 10 ÷ 5 = 2 MADs.
  2. A gap of 2 MADs means the typical scores are well separated, though some scores overlap, so the teams differ noticeably.

Scoring: 1 point for each part.

Comparing Two Populations lessonComparing Two Populations worksheetComparing Two Populations testComparing Two Populations quiz