Each month the National Association of Purchasing Managers publishes the NAPM index. One of the questions asked on the survey to purchasing agents is: Do you think that the economy is expanding? Last month, of the 300 responses, 160 answered yes to the question. This month, 170 of the 290 responses indicated that the economy is expanding. If youre testing to find if a larger proportion of agents believe that the economy is expanding this month, what is your computed test statistic?

• t = -1.07

• z = -1.29

• z = -1.11

• t = -1.25