Question 386715
{{{9600 = 4000(1 + r)^8}}};
{{{9600/4000 = (1+r)^8}}};
{{{root(8,9600/4000) = 1 + r}}};
{{{r = root(8,9600/4000) - 1}}}, or
11.6 %, to 1 decimal place.