Customers service representatives attempt to sell new products to certain customers when they call in.  In order for the "cross sell" to be profitable service representatives need to get more than 10% of customers to buy the new product.  In a sample of one team of service representatives they offered the new product to 500 customers and 67 made the purchase.  Management wants proof at the .01 level of significance that the team sells to more than 10% of customers.  Note that the null hypothesis is that the population proportion<=.1.  What is the test statistic?