An Exponentially Decaying Substance Was Weighed Every Hour and the Results

Short Answer

An exponentially decaying substance was weighed every hour and the results are given below.What is the approximate half-life, in hours, of the substance? Round to 1 decimal place.
$\begin{array}{cc}\text { Time } & \text { Weight (in grams } \\9 \mathrm{am} & 16 \\10 \mathrm{am} & 14.623 \\11 \mathrm{am} & 13.364 \\12 \text { noon } & 12.214 \\1 \mathrm{pm} & 11.163\end{array}$