Chapter 11 - 11.7 - Probability - 11.7 Exercises - Page 837: 64b

The approximate value of $\pi$ in this case is 3.2. See the explanation

Out of 100 tosses, the coin covers a vertex of one of the squares on the grid 80 times so equating the probability from part (a) (which is $\frac{\pi}{4}$) and the result gives : $\frac{\pi}{4} = \frac{80}{100}$ $\pi = 3.2$ The approximate value of $\pi$ in this case is 3.2.