The length, in words, of the essays written for a contest are normally distributed with an unknown population mean and standard deviation. A random sample of 35 essays is taken and results in a sample mean of 2230 words and sample standard deviation of 271 words.

df...3334353637t0.10...1.3081.3071.3061.3061.305t0.05...1.6921.6911.6901.6881.687t0.025...2.0352.0322.0302.0282.026t0.01...2.4452.4412.4382.4342.431t0.005...2.7332.7282.7242.7192.715

What is themargin of error for a90% confidence interval estimate for the population mean using the Student's t-distribution?

• Round the final answer to two decimal places.