Answer:
Mean: For this case would be not useful since in the stem leaf plot is difficult to find this measure with this chart
Explanation:
We want construct a stem and leaf plot and we want to find the measure least useful.
And for this case if we analyze the option we have:
Range: That very useful and it can be extracted from the stem and leaf plot
Median: It could be easy to find it with the stem leaf plot
Mode: With a stem leaf plot we can find easily the most repeated value
Mean: For this case would be not useful since in the stem leaf plot is difficult to find this measure with this chart