First, we need the total number of people that used transportation.
8+20+20+32 = 80
Next, we can make a ratio that represents the number of people who used bikes out of the total number of people. 8/80. Next, we set this equal to the ratio x/100 with x being the percent of people who used a bike.
8/80 = x/100
Finally, we solve for x.
(100*8)/80 = x
800/80 = x10 = x
x equals 10, meaning 10% of people surveyed used a bike to get to the park.