#### To determine

**To find:**

How fast is the water skier rising as she leaves the ramp

#### Answer

The rate of rising of the water skier is 7.7 ft /s

#### Explanation

**1. Formula:**

Constant multiple rule:

ddxCf(x)=Cddx(fx)

**2. Given:**

dzdt=30 ft/s

3. **Calculation:**

By using the Pythagorean Theorem

Z^{2} = 15^{2 }+ 4^{2} = 225 + 16 = 241

Therefore, Z= 241

By using similar triangle property

y4=z241

⇒y=4z241

Differentiate with respect to t

dydt=ddt(4z241)

By using constant multiple rule

dydt=4241dzdt

Since, dzdt=30

dydt=4241*30

dydt=7.7

**Conclusion:**

Therefore, the rate of rising of the water skier is 7.7 ft /s