Answer
${{\$}} 18,000$
Work Step by Step
$50=\displaystyle \frac{95.0}{1+2.78(1.064)^{-x}}$
$1+2.78(1.064)^{-x}=\displaystyle \frac{95.0}{50}$
$2.78(1.064)^{-x}=1.9-1$
$(1.064)^{-x}=\displaystyle \frac{0.9}{2.78}\qquad $ (apply log)
$-x\displaystyle \log 1.064=\log\frac{0.9}{2.78}$
$x=-\displaystyle \frac{\log\frac{0.9}{2.78}}{\log 1.064}\approx 18.180$ thousands of dollars
Round to the nearest thousand: ${{\$}} 18,000$
