Question

The dot plots below show the scores for a group of students who took two rounds of a quiz:

Two dot plots are shown one below the other. The title for the dot plot on the top is Round 1 and the title for the bottom plot is Round 2. Below the line for each dot plot is written Score. There are markings from 5 to 9 on the line at intervals of one. There are 2 dots above the mark 5, 3 dots above the mark 6, 4 dots above the mark 7, and 1 dot above the mark 8. For the bottom dot plot there are 6 dots above the mark 6, 2 dots above the mark 8, and 2 dots above the mark 9.

Which of the following inferences can be made using the dot plot?

The range of each round is the same.
There is no overlap between the data.
Round 1 scores were higher than round 2 scores.
Round 2 scores were lower than round 1 scores.

Answer 1

The inference that can be made using the dot plot is:

The range of round 1 is greater than the round 2 range

Explanation:

Round 1:

Score Frequency

1 0

2 2

3 3

4 2

5 1

Hence, the minimum score of Round 1 is: 2

maximum score is: 5

Hence, Range=Maximum value-Minimum score

=5-2

=3

Similarly, Round-2

Score Frequency

1 0

2 0

3 0

4 4

5 4

Hence, the minimum score of Round 1 is: 4

maximum score is: 5

Hence, Range=Maximum value-Minimum score

=5-4

=1

The scores of round 2 are higher than round-1.

Since round 2 have a higher frequency for higher scores as compared to round-1.

Hence, Range of round 1 is greater than the range of Round-2.