Question

Please help me, I'm lost.

Astronomers classify stars according to their brightness by assigning them a stellar “magnitude.” The higher the magnitude the dimmer the star. The dimmest stars visible to the naked eye have stellar magnitudes of 6. The table below shows the relative brightness of different stellar magnitudes.

Answer 1

a. y = 250 (0.4)^x

b. 0.066

Explanation:

The equation can be modeled as a geometric sequence, where the first term is 100 and the common ratio is 0.4.

y = 100 (0.4)^(x − 1)

This can also be simplified to:

y = 250 (0.4)^x

When x = 9:

y = 250 (0.4)^9

y = 0.066