The speed of light in a medium is always slower than the speed of light in a vacuum. To calculate the speed of light in ethyl alcohol, we need its refractive index.

Here's how to find it:

1. Look up the refractive index of ethyl alcohol. This value can be found in various resources like scientific databases or textbooks. The refractive index of ethyl alcohol (at a specific wavelength of light, typically 589 nm) is approximately 1.36.

2. Use the formula:

Speed of light in medium = Speed of light in vacuum / Refractive index of the medium

3. Calculate:

Speed of light in vacuum (c) = 299,792,458 meters per second

Refractive index of ethyl alcohol (n) = 1.36

Speed of light in ethyl alcohol = c / n = 299,792,458 m/s / 1.36 ≈ 220,435,634 m/s

Therefore, the speed of light in ethyl alcohol is approximately 220,435,634 meters per second.