Decrease 72 in a ratio of \( 7: 18 \).

To decrease 72 in a ratio of \( 7: 18 \), you'll first want to find the total parts of the ratio, which is \( 7 + 18 = 25 \). Now, we can calculate how much to decrease. Each part in the ratio represents a fraction of 72: \[ \text{Part Value} = \frac{72}{25} = 2.88 \] Next, multiply the part that corresponds to the decrease (7 parts) by the value of each part: \[ \text{Decrease} = 7 \times 2.88 = 20.16 \] Finally, subtract this decrease from 72: \[ 72 - 20.16 = 51.84 \] So, decreasing 72 in a ratio of \( 7: 18 \) gives you approximately \( 51.84 \).