p(t)=100(21)8.02tRadioactive isotopes are unstable atoms that decay into other atoms. lodine−131 is a radioactive isotope. The function models p, the percentage of iodine−131 atoms remaining in a sample after t days. To the nearest tenth of a percent, what percent of iodine−131 atoms remain in the sample after 10 days?(Ignore the % symbol when entering your answer. For example, if the answer is 11.2%, enter 11.2 .)
Q. p(t)=100(21)8.02tRadioactive isotopes are unstable atoms that decay into other atoms. lodine−131 is a radioactive isotope. The function models p, the percentage of iodine−131 atoms remaining in a sample after t days. To the nearest tenth of a percent, what percent of iodine−131 atoms remain in the sample after 10 days?(Ignore the % symbol when entering your answer. For example, if the answer is 11.2%, enter 11.2 .)
Identify Function and Value: Identify the given function and the value of t for which we need to find p(t). The function given is p(t)=100×(21)8.02t, which models the percentage of iodine−131 atoms remaining after t days. We need to find the percentage remaining after t=10 days.
Substitute Value into Function: Substitute the value of t into the function.We substitute t=10 into the function to find p(10).p(10)=100×(21)8.0210
Calculate Exponent: Calculate the exponent.We need to calculate (21)(8.0210).First, we calculate the fraction8.0210.8.0210≈1.247Now we raise (21) to the power of 1.247.(21)1.247
Use Calculator for Calculation: Use a calculator to find the value of (21)1.247.Using a calculator, we find that (21)1.247≈0.421.
Find Percentage by Multiplication: Multiply the result by 100 to find the percentage.Now we multiply the result from the previous step by 100 to find the percentage of iodine-131 remaining after 10 days.p(10)=100×0.421p(10)≈42.1
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