# sd1 t3 10.1 ⁂ 22 March 2013 Name:

Does juggling slow down my running? I went to the track and ran twelve laps of the track, alternating joggling (juggling while running) laps with pure running laps. I juggled when I ran odd numbered laps and ran without juggling for even numbered laps. After twelve laps I had six of each type of lap, creating two samples. To run this study you will have to make two sets of calculations for the two confidence intervals - one for each set of lap times. The data are lap times per lap of a 400 meter track run on 17 March 2013. Use a confidence level c of 0.95 for this study.

joggling lapsrunning laps
149145
148143
148146
149146
150142
146136
1. Calculate the sample size n for each sample.
2. Calculate the sample mean x for each sample.
3. Calculate the sample standard deviation sx for each sample.
4. Calculate the standard error of the mean (SE).
5. For a confidence level of 95%, calculate the t-critical.
6. Calculate the margin of error E for the mean.
7. For a confidence level of 95%, calculate the lower bound for the mean for each sample?
8. For a confidence level of 95%, calculate the upper bound for the mean for each sample?
9. Hand draw sketches of the two confidence intervals including the lower bounds, sample means, and upper bounds.
10. The bigger the lap time, the slower the speed on the lap. The smaller the lap time, the faster the speed on the lap. Are my mean lap times for joggling and running different?
11. If my mean lap times are different, is that difference statistically significant?
12. Does juggling slow down my running? Support your answer with the data above.