A study was performed to determine the percentage of people who wear life vests while out on the water. A researcher believed that the percentage was different for those who rode jet skis compared to those who were in boats. Out of 200 randomly selected people who rode a jet ski, 81% wore life vests. Out of 400 randomly selected boaters, 88% wore life vests. Using a 0.01 level of significance, test the claim that the proportion of people who wear life vests while riding a jet ski is not the same as the proportion of people who wear life vests while riding in a boat. Let jet skiers be Population 1 and let boaters be Population 2.

Step 2 of 3 : Compute the value of the test statistic. Round your answer to two decimal places.