Question

find the mean, median, and mode(s) of the data in the following stem - and - leaf plot. the leaf represents the ones digit.
0|9
1|6
2|1125
3|6
part 1 of 3
find the mean. round your answer to one decimal place, if necessary.
mean:
part 2 of 3
find the median. round your answer to one decimal place, if necessary.
median:
part 3 of 3
find the mode(s). if there is more than one, separate them with commas.
there is no mode.
there is at least one mode.
mode(s):

Explanation:

Step1: Write out the data set

The stem - and - leaf plot gives the data set: 9, 11, 16, 21, 21, 22, 25, 36.

Step2: Calculate the mean

The mean $\bar{x}=\frac{\sum_{i = 1}^{n}x_{i}}{n}$, where $n = 8$ and $\sum_{i=1}^{8}x_{i}=9 + 11+16+21+21+22+25+36=161$. So $\bar{x}=\frac{161}{8}=20.125\approx20.1$.

Step3: Calculate the median

Since $n = 8$ (an even number), the median is the average of the $\frac{n}{2}$th and $(\frac{n}{2}+1)$th ordered values. The ordered data set is 9, 11, 16, 21, 21, 22, 25, 36. The 4th value is 21 and the 5th value is 21. So the median $=\frac{21 + 21}{2}=21.0$.

Step4: Calculate the mode

The mode is the value that appears most frequently. In the data set 9, 11, 16, 21, 21, 22, 25, 36, the number 21 appears twice and the other numbers appear once. So the mode is 21.

Answer:

Part 1 of 3: Mean: 20.1
Part 2 of 3: Median: 21.0
Part 3 of 3: Mode(s): 21