In a random sample of 50 Americans five years ago (Group 1), the average credit card debt was $5,598. In a random sample of 50 Americans in the present day (Group 2), the average credit card debt is $6,499. Let the population standard deviation be $1,155 five years ago, and let the current population standard deviation be $1,699.

Using a 0.01 level of significance, test if there is a difference in credit card debt today versus five years ago. What is the test statistic? (Round to 4 decimal places)