Question

The table below illustrates the decay of a sample of radioactive uranium.
Time in Days, x 0 1 2 3 4 5
Sample Remaining (grams), U 500 255 130 66 34 17

Which equation best models this set of data where U represents the amount of sample remaining, in grams, at time x?


A. U = 26.7x2 - 223.9x + 481.1

B. U = 500(0.51)x

C. U = 500(0.49)x

D. U = 392 - 90.2x

Answer 1

you start with 500 so it is going to look like \(500\times (b)^x\) for some \(b\)

Answer 2

to find b, take the ratio of any pair of outputs. you get for example \(\frac{255}{500}=.51\) so that is your b

Answer 3

so what answer choice would that be ?

Answer 4

@satellite73 what answer choice would that be?

Answer 5

\(500\times (.51)^x\)

Answer 6

@satellite73 thank you so much