2. Determine the simple interest rate for each investment Round your answers to one decimal place,where necessary. a) 4000 grows to 5000 in 10 years.

## Step 1: Calculate the interest earned.<br />### The interest earned is the difference between the final amount and the principal amount. $I = \$5000 - \$4000 = \$1000$.<br /><br />## Step 2: Calculate the simple interest rate.<br />### We use the formula $I = Prt$, where $I$ is the interest, $P$ is the principal, $r$ is the rate, and $t$ is the time. We have $I = \$1000$, $P = \$4000$, and $t = 10$ years. We need to solve for $r$. $1000 = 4000 \cdot r \cdot 10$. $1000 = 40000r$. $r = \frac{1000}{40000} = \frac{1}{40} = 0.025$. Converting to a percentage, we get $0.025 \times 100\% = 2.5\%$.