The proportion of drivers who employ seat belts depends upon things like age (young people are more likely to go unbelted) and gender (women are more likely to use belts). It also depends upon local law. In New York City, police can stop driver who isn't belted. In Boston at the time of survey, police could cite a driver for not wearing a seat belt only if driver had been stopped for some other violation. Here are data from observing random samples of female Hispanic drivers in these two cities:
City Drivers Belted
New York 220 183
Boston 117 68
Compute the z test statistic. Give your answer to two decimal places.