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Math Challenge I-A + I-B Counting and Probability
Math Challenge I-A + I-B Counting and Probability
Lecture 9, Problems 9.10 c and 9.10 b
for 9.10 b, I got 84.9 because 60+64+78+80+90+92+94+95+97+99=849, and $\frac {849}{10}$=84.9 The answer says that it is 85
for 9.10 c, I got 86.6 or $\frac {433}{5}$ because the new mean is $\frac {849+450}{15}$=86.6 The answer says that it is $\frac {1300}{15}$
Re: Math Challenge I-A + I-B Counting and Probability
You are correct. The way the problem was written the sum of all the grades is $849$. This was a typo, as we intended the sum to be $850$ to make the calculations easier. The second to last grade should have been $98$, not $97$.
Thanks for letting us know!
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