Chapter 9 - Section 9.3 - Geometric Sequences; Geometric Series - 9.3 Assess Your Understanding - Page 665: 85

${{\$}} 47,271.37$

Increasing x by $ 3\%$ is multiplying it with $1+0.03=1.03.$ $a_{1}=42,000$ $a_{2}=42,000(1.03)$ $a_{3}=42,000(1.03)^{2}...$ This is a geometric series with $a_{1}=42,000$, $r=1.03,\ \quad a_{n}=a_{1}r^{n-1}$ We want $a_{5}=42,000(1.03)^{4}\approx 47,271.37$