Late delivery ~ Amazon wants to maintain the existing customer loyalty. Initial data analysis revealed that the proportion of orders that are delivered late to the customers is 0.102. They take measures to improve the quality of their delivery service. Alexa wants to determine if the actual proportion of orders that are delivered late to the customers is different from the value reported by the initial data analysis. In a recent random sample of 191 orders, Alexa found that 13 orders are delivered late. A normal distribution is used to carry out the following hypothesis test: H0:p= 0.102 vs HA:p≠ 0.102. What is the test statistic for this hypothesis test?