MS 150 quiz 13 § 11.2 • Name:

01 May 2009

On the college COMET entrance test the essay score counts towards 50% of the criterion used for admission status. A perfect essay is a score of 50. Writing a good essay requires a strong command of English vocabulary, grammar, and the essay form. The essay provides a strong indicator of academic preparation. Which high school performed better on the essay spring 2009 - Xavier or SDA here on Pohnpei? This quiz examines this question.

1. __________ What is the sample mean for Xavier?
2. __________ What is the sample mean for Pohnpei SDA?
3. ____________________ What is the p-value based on a two-tailed t-test for independent samples? [Keep four decimal places]
4. ____________________ What is the maximum confidence that the difference is statistically significant? [Keep four decimal places]
5. ____________________ Should you reject or fail to reject a null hypothesis of no difference in the means for an alpha of 5%?

Hypothesis Testing
Statistic or Parameter	Symbol	Equations	OpenOffice
Relationship between confidence level c and alpha α for two-tailed tests		1 − c = α
Calculate t-critical for a two-tailed test using α = 0.05:	tc		=TINV(α;df)
Calculate a t-statistic t	t		=(x - μ)/(sx/SQRT(n))
Calculate a two-tailed p-value from a t-statistic	p-value		= TDIST(ABS(t);df;2)