The angle of incidence for a ray of light passing through an equilateral glass prism is equal to its angle of emergence. Also, the angle of emergence is `3//4` times the angle of prism. Calculate the angle of deviation and refractive index of prism's material.

Explanation

To solve the problem, we need to find the angle of deviation and the refractive index of the prism's material based on the given conditions.

### Step-by-Step Solution:

1. **Understanding the Problem:**
We are given that the angle of incidence (I) is equal to the angle of emergence (E) and that the angle of emergence is \( \frac{3}{4} \) times the angle of the prism (A). Since it is an equilateral prism, the angle A is \( 60^\circ \).

2. **Finding the Angle of Emergence:**
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