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Help with Algebra problem?

A student is trying to determine the half-life of radioactive iodine-131. He measures the amount,A , of iodine-131 in a sample solution every 8 hours. His data are shown in the table.

Time(h) = Amount(g)

0 = 5.33

8 = 5.16

16 = 5

24 = 4.83

32 = 4.74

40 = 4.6

48 = 4.48

(a) Find an appropriate exponential model of the data points.

Amount at time t, A(t) = ?

(b) Find the half-life of idoine-131 according to the exponential model in part (a).

Half-life, t = ?

1 Answer

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  • nosi
    Lv 4
    8 years ago
    Favorite Answer

    I'm guessing that if you are in this class, you have a graphing calculator. enter your data into L1 and L2, then run LinReg and tell it to StoreRegEQ in Y1. Should give you something like -.02075x+5.329. Looking at the table, you find the half-life to be about 128 hours.

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