An engineer invested $\$10,\!000$ in a six-month savings certificate that paid a simple annual interest rate of $12\%$. After six months, she invested the total value of her investment in another six-month certificate. After six more months, the investment was worth $\$11,\!130$. If the annual interest rate of the second certificate is $r\%,$ then what is $r?$

clairepow Feb 14, 2021

#1**0 **

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11 130 =(10000 + 10000*.12 /2 ) * (1+r/2)

where r is in decimal form %

r =10 %

ElectricPavlov Feb 14, 2021