Dominate versus Non-Dominate Hand Rochelle Mills and Courtney Preister

Hypotheses Step 1: Null Hypothesis: The average difference of times between writing with the dominate and non-dominate hand will be zero. Alternative Hypothesis: The average difference of times between writing with the dominate and non-dominate hand will be greater than zero.

Conditions Step 2: SRS (Simple Random Sample): The data came from a randomized, matched pairs experiment. We can generalize the results of this study to the population because we consider our 30 subjects as an SRS from the population. Normality The stem plot and Normal probability plot of the differences show that the distribution is symmetric and appears reasonably Normal in shape. We have no reason to question the Normality of the population. Independence We are willing to assume that the 30 subjects’ differences in writing the word “holiday” are independent observations.

SubjectDominate (seconds)Non-Dominate (seconds) Difference

SubjectDominate (seconds)Non-Dominate (seconds) Difference

Calculations  Summary: Mean 3.76 Standard deviation 1.30  Test statistic T-test  t=  p-value=.0000

Interpretation  T-interval (3.2689, )  With 95% confidence, we estimate the mean time (seconds) for writing the word “holiday”, with dominate versus non-dominate hand, to fall between and

Bias  Capitalizing  Competition  Confusion  Illegibility

Conclusion  The p-value is small enough to reject the null hypothesis. We can conclude that it will take longer to write with your non-dominate hand than your dominate hand

Females verses Males  The average difference time for females was 3.58 seconds  The average difference time for males was 4.00 seconds  We think this was because guys tend to write faster with their dominate hand, causing a bigger difference

Interesting Facts about Lefties  10 to 12 percent of the human population is dominantly left handed In our study 13% of the SRS were left handed!  Lefties have long suffered. In India and Indonesia, eating with the left hand is considered impolite. Chinese characters prove extremely difficult to write with the left hand. Not so long ago, teachers slapped the wrists of left-handed American elementary students.