Question

multiple choice
which stem-and-leaf plot shows a data set with a mean that is greater than its
median?
press to hear a reminder or hint for this problem.
because each data set has 10 values, you can write the
data sets one on top of the other and find all three
medians at once!
a: 1|2; 2|6; 3|8 8 9; 4|1 2 2 3 5; 2|6=26
b: 1|1 2 2 4 5; 2|2 4 6; 3|6; 4|8; 2|6=26
c: 1|8; 2|6 7; 3|3 3 3 3 9; 4|0 8; 2|6=26

Explanation:

Step1: List data for each plot

Plot A: 12,26,38,38,39,41,42,42,43,45
Plot B:11,12,12,14,15,22,24,26,36,48
Plot C:18,26,27,33,33,33,33,39,40,48

Step2: Calculate median for each (10 values: avg 5th&6th)

Plot A median: $\frac{39+41}{2}=40$
Plot B median: $\frac{15+22}{2}=18.5$
Plot C median: $\frac{33+33}{2}=33$

Step3: Calculate mean for each

Plot A mean: $\frac{12+26+38+38+39+41+42+42+43+45}{10}=\frac{366}{10}=36.6$
Plot B mean: $\frac{11+12+12+14+15+22+24+26+36+48}{10}=\frac{210}{10}=21$
Plot C mean: $\frac{18+26+27+33+33+33+33+39+40+48}{10}=\frac{330}{10}=33$

Step4: Compare mean vs median

Plot A: 36.6 < 40; Plot B:21 >18.5; Plot C:33=33

Answer:

B. The middle stem-and-leaf plot