Answer:
Two standard deviations
Step-by-step explanation:
The Z score is obtained using the mean and standard deviation, according to the empirical. Rule, which gives percentage of values that lie within an interval estimate in a normal distribution ;
one standard deviation lie within 68% of the mean
Two standard deviations lie within 95%
Three standard deviations lie within 99.7%
Hence, for the question given, 95% fall within 2 standard deviations of the mean
For this question, the time given confuses me. I know the rate of return is just total return divided by divided by investment, Assuming that Matt received the $400 in dividends as cash payouts, and they weren't reinvested into buying shares of the stock, then his total return over two years was $500, Now, if Matt's dividends were reinvested into the stock - and if you have a 401(k) or IRA, that's what usually happens - then his ROI would have been only 6% because he only made a profit of $100 on an investment of $1500. Note: In the real world, in current market conditions, Matt probably would have got about a 5% return on a good stock, and Bella would have received about 0.05% on a savings account.
hope this helped you ;)
5m + 4m = 72
Combine like terms.
9m = 72
Divide both sides by 9.
m = 8
This figure, I believe, is a triangular prism.