Final answer:
The index of refraction can be calculated using the formula n = c/v, where n is the index of refraction, c is the speed of light in a vacuum, and v is the speed of light in the medium. The index of refraction of the medium is approximately 1.154.
Step-by-step explanation:
The index of refraction of a medium can be calculated using the formula:
n = c/v
where n is the index of refraction, c is the speed of light in a vacuum (approximately 3.00 x 10^8 m/s), and v is the speed of light in the medium.
In this case, the speed of light in the medium is given as 2.60 x 10^8 m/s. Plugging this value into the formula, we get:
n = (3.00 x 10^8 m/s) / (2.60 x 10^8 m/s)
Simplifying the expression, we find that the index of refraction of the medium is approximately 1.154.