A researcher would like to examine how the chemical tryptoph

A researcher would like to examine how the chemical tryptophan, contained in foods such as turkey, can affect mental alertness. A sample of n = 7 college students is obtained and each student’s performance on a familiar video game is measured before and after eating a traditional Thanksgiving dinner including roast turkey. Mental alertness was measured using a scale that ranged from 1 to 20 with a higher score indicating higher levels of mental alertness. Conduct a one-tailed test at the .01 alpha level to determine if the increase in tryptophan decreased mental alertness in this sample.

a. what is the appropriate null and alternative hypothesis for this example?

b. What is the critical value of t for a .01, one-tailed test?

c. What is the standard error of the mean and calculated value of t? Be sure to calculate the SS and the sample variance.

d. Are the data sufficent to conclude that the increase in tryptophan decreased mental alertness for this sample?

e. Write and APA format sentence to report the results of this study.

f. Compute Cohen\'s d, r^2, and a 99% Confidence Interval for this study.

Solution