I'm getting this wrong. Not sure what I'm doing that is incorrect.

170 plus or minus 2.576 square root .170 (1-.170) divided by 200. I'm getting lower and upper limit answer= 169.932, 170.068. Please help.

Out of 200 people sampled, 170 had kids. Based on this, construct a 99% confidence interval for the true population proportion of people with kids. --Use z = 2.576 for a 99% confidence interval. Give your answers to three decimals