Final answer:
The index of refraction for sapphire is approximately 1.775.
Step-by-step explanation:
The index of refraction, n, can be calculated using the equation n = c/v, where c is the speed of light in a vacuum and v is the speed of light in the material. Since the speed of light in sapphire is given as 1.69 x 10^8 m/s, we can plug this value into the equation to find the index of refraction for sapphire.
n = c/v
n = (3.00 x 10^8 m/s) / (1.69 x 10^8 m/s)
n ≈ 1.775
Therefore, the index of refraction for sapphire is approximately 1.775.