Question

Use the graph showing Jamie's account balance to answer the question what is the interest rate on Jamie's account?

A. 1.9%
B. 2.2%
C. 18.3%
D. 22.5%

Answer 1

Answer: 12 yers

Explanation:

Answer 2

notice, the graph starts off with an account balance of $10, at the 10 over the y-axis, that means the initial amount in the account, or what he initially deposited was 10 bucks.

now... let's use any of the points, say hmm the 2, 10.44.

after 2 years, he's got an extra 44 cents in it, went up to 10.44.

bearing in mind that is a linear graph, and thus is a simple interest rate.


`\bf \qquad \textit{Simple Interest Earned Amount}\\\\ A=P(1+rt)\qquad \begin{cases} A=\textit{accumulated amount}\to &10.44\\ P=\textit{original amount deposited}\to& \$10\\ r=rate\to r\%\to (r)/(100)\\ t=years\to &2 \end{cases} \\\\\\ 10.44=10(1+r2)\implies \cfrac{10.44}{10}=1+2r\implies 1.044=1+2r \\\\\\ 1.044-1=2r\implies \cfrac{0.044}{2}=r\implies 0.022=r \\\\\\ 0.022=\cfrac{r}{100}\implies 0.022\cdot 100=r\implies \stackrel{\%}{2.2}=r`