This is a variation acitivity: for a given interest rate, simple interest varies jointly as principal and time. if $2000 left in an account for 4 year earns interest of $320, how much interest would be earned in if you deposit $5000 for 7 years? to set it up so far for step 1, i have s = kpts = simple interestp = principalt = timei know i have to solve for k first using the information then fill in k to get the second half for the answer. i just don’t know how to do that with this question considering the wording.