# q05 5.1 RipStik Learning Curve • Name:

My youngest daughter wanted to learn to ride a RipStik. She had made a couple of attempts on two prior days without any success, she would fall off almost as soon as she started moving. On Wednesday evening I took her out to the movie theater parking lot and worked with her on learning to ride the RipStik. The data in the table indicates her attempt number and the number of seconds (s) she remained up, rolling, and successfully riding the RipStik [rolling time (s)]. With each attempt she was generally, but not always able to ride longer. No children were hurt in the production of this data.

AttemptRolling time (s)
10.0
20.5
30.9
42.6
58.5
63.6
75.8
84.8
912.3
107.9
118.3
1210.4
139.3
1410.6
1510.1
1616.6
1712.0
186.3
1. __________ Find the sample size n for the data.
2. __________ Find the rolling time (s) mode.
3. __________ Find the rolling time (s) median.
4. __________ Find the rolling time (s) sample mean x.
5. sx = 4.57 Freebie: This is the standard deviation sx for the rolling time (s). If you obtain a different value, then you typed in the wrong data!
6. __________ Calculate the slope of the linear trend line for the data.
7. __________ Calculate the y-intercept of the linear regression for the data.
8. __________ Use the slope and intercept to predict the rolling time (s) for a 20th attempt.
9. __________ Use the slope and intercept to predict the attempt at which she will have a rolling time of 30 seconds.
10. __________ Does the relationship appear to be linear, non-linear, or random?
11. __________ Is the correlation positive, negative, or neutral?
12. __________ Determine the correlation coefficient r.
13. __________ What is the strength of the correlation: strong, moderate, weak, or none?
14. __________ Determine the coefficient of determination r².
15. __________ What percent of the variation in the attempt number explains the variation in the rolling time data?
16. p(3) = ______________ What is the probability of rolling a three on a six-sided die numbered from one to six?
17. p(odd) = ______________ What is the probability of rolling an odd number on an nine sided die numbered one to nine?
18. Can a die be one-sided? What shape would a one-sided die be?