Answer:
By 0.75
Step-by-step explanation:
From the stem-and-leaf plot you can find James's scores:
79, 81, 83, 83, 83, 85, 85, 88, 94, 99.
The mode is 83 (most often score). If he drops his scores from the first two weeks, his mode score increases by 2. This means that the mode became 85 and the data looks like
79, 81, 83, 85, 85, 88, 94, 99.
Now find two means.
1. The old mean:
[tex]\dfrac{79+81+83+83+83+85+85+88+94+99}{10}=\dfrac{860}{10}=86;[/tex]
2. The new mean:
[tex]\dfrac{79+81+83+85+85+88+94+99}{8}=\dfrac{694}{8}=86.75;[/tex]
Thus, the mean will increase by 0.75.
