In January, the depth of a lake was 873 feet. In August, the depth of the lake was 698.4 feet. What is the percentage decrease of the depth of the lake from January to August?

1 answer

To find the percentage decrease in the depth of the lake from January to August, we can use the following formula for percentage decrease:

\[ \text{Percentage Decrease} = \frac{\text{Original Value} - \text{New Value}}{\text{Original Value}} \times 100 \]

In this case, the original value (depth in January) is 873 feet, and the new value (depth in August) is 698.4 feet.

First, we calculate the decrease in depth:

\[ \text{Decrease} = 873 - 698.4 = 174.6 \text{ feet} \]

Next, we plug the values into the percentage decrease formula:

\[ \text{Percentage Decrease} = \frac{174.6}{873} \times 100 \]

Calculating the fraction:

\[ \frac{174.6}{873} \approx 0.2005 \]

Now multiply by 100 to convert it to a percentage:

\[ 0.2005 \times 100 \approx 20.05% \]

Therefore, the percentage decrease in the depth of the lake from January to August is approximately 20.05%.