Calculate z-statistic of a population mean.

Keith sampled 10 private universities in Colorado and recorded the tuition cost. Keith wants to test the hypothesis that the tuition of these 10 universities is more expensive than the national average tuition, which is $29,056 with a population standard deviation of $3,339.

If the sample mean is $31,650, what is the z-score? Answers are rounded to the hundredths place.

• a.)0.13
• b.)2.46
• c.)-2.94
• d.)-0.78