The dot plots below show the distances traveled by two groups of bikers: Two dot plots are labeled Group A and Group B. The hori
zontal axis is labeled Distance Traveled and marked from 15 to 40 at increments of 5 for both dot plots. Group A shows 9 dots on 15, 8 dots on 20, 3 dots on 25, 6 dots on 30, 4 dots on 35. Group B shows 10 dots on 20, 6 dots on 25, 4 dots on 30, 9 dots on 35 and 6 dots on 40. Which of the following inferences can be made using the dot plots?
There is no overlap between the data.
The range of the two groups is different.
Group A has a higher mean than group B.
Group B has a higher mean than group A.
The correct answer is that Group B has a higher mean.
The range of Group A is 35-15 = 20. The range of Group B is 40-20 = 20. There is no difference.
The mean of Group A is found by adding all of the data points and dividing by the number of data points: 15(9)+20(8)+25(3)+30(6)+35(4)=690; 690/30 = 23.
The mean of Group B is: 20(10)+25(6)+30(4)+35(9)+40(6)=1025; 1025/35 = 29.29
