Suppose you have a project that has a $0\mathrm{.}3$ chance of tripling your investment in a year and a $0\mathrm{.}7$ chance of halving your investment in a

year. What is the standard deviation of the rate of return on this investment? $($Do not round intermediate calculations. Enter your

answer as a percentage rounded to $2$ decimal places.$)$

Standard deviation

$\%$