\( \begin{array}{l} \text { Example: } 188 \text { meters to } 42 \text { meters } \\ \text { percent change }=\frac{188-42}{188}=\frac{146}{188} \\ x=\frac{146}{100} \\ \frac{188 x}{188}=\frac{14600}{188} \\ x=77 \\ \text { Answer: } 77.7 \% \text { decrease }\end{array} \)

Let's break down the example step by step to understand how to calculate the percent change. 1. **Identify the known values:** - Initial value (old value): \( 188 \) meters - Final value (new value): \( 42 \) meters 2. **Calculate the change in value:** \[ \text{Change} = \text{Initial value} - \text{Final value} = 188 - 42 = 146 \text{ meters} \] 3. **Calculate the percent change:** The formula for percent change is given by: \[ \text{Percent Change} = \frac{\text{Change}}{\text{Initial value}} \times 100 \] Substituting the values we have: \[ \text{Percent Change} = \frac{146}{188} \times 100 \] 4. **Calculate the fraction:** First, we calculate \( \frac{146}{188} \): \[ \frac{146}{188} \approx 0.7766 \] 5. **Convert to percentage:** Now, multiply by \( 100 \): \[ 0.7766 \times 100 \approx 77.66 \] 6. **Final result:** The percent change is approximately \( 77.66\% \). Since the value decreased, we can say: \[ \text{Answer: } 77.7\% \text{ decrease} \] Thus, the final answer is a \( 77.7\% \) decrease.