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%
Question
Answer:
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.
[tex]\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 \frac{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[/tex]
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10 months ago
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