I cant figure out the t-value and the z-value for this problem, My textbook's z-card is wrong!

16. A sample of 20 international students attending an urban U.S. university found that the average amount budgeted for expenses per month was $1,612.50 with a standard deviation of $1,179.64. Find a 95% confidence interval for the mean monthly expense budget of the population of international students. Use the appropriate formula and verify your result using the Confidence Intervals workbook.
Expense Budget
Confidence Interval for Population Mean, Standard Deviation Unknown
Alpha	0.05
Sample standard deviation	1179.64
Sample size	20
Sample average	1612.5
Confidence Interval
t-value
Error
Lower
Upper