The National Football League (NFL) combine is a forum in which players who want to play in the NFL demonstrate various skills. One skill that is measured is the 40-yard dash. Go to www.pearsonhighered.com/sullivanstats to obtain the data file 13_1_23 using the file format of your choice for the version of the text you are using.
(a) What type of variable is 40-yard dash time?
(b) Excluding quarterback (QB), the skill positions are cornerback (CB), safety (S), running back (RB), and wide receiver (WR). Suppose we want to know whether there is a difference between the 40-yard dash times for these positions.
What would be the null and alternative hypotheses?
(c) Assuming we treat the players as a random sample of all players in each position, explain why we may use a one-way ANOVA to determine if there is a significant difference between 40-yard dash times for these positions. How many means are being compared?
(d) Does the evidence suggest a difference exists for the 40-yard dash times for the skill positions (except quarterback)? Use the a = 0.05 level of significance.
(e) Draw boxplots of the 40-yard dash times for the skill positions (except quarterback) to support the results from part (d).