Help with a statistics problem!

I have to calculate the T statistic. To solve I need to have the sample mean, population mean, sample size and standard deviation. I am confused on how to calculate the sample and population means.

The problem only says that there was a poll done on 2,000 adults. 1,600 support a membership. The problems wants me to figure out if the proportion of people who support the membership is significantly different from 85%. But the first step is to figure out the T Statistic. How do I figure it out?