How did I get the below practice question wrong?

A sample of 10 widgets has a mean of 32.750 and standard deviation of 5.500. At 90% confidence, the lower limit with 3 decimal places is

Answer:

29.889

(29.562)

Here's the work:

Margin of error = 1.645*5.500/10^0.5= 2861.071

Lower limit = mean - margin of error

Lower limit = 32.75-2.861070713 or 29.889