The standard deviation represents the range on either

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The standard deviation represents the range, on either side of the mean, in which the majority of participant samples will fall. The range between 1 deviation measure greater and less than the mean represents 68% of the samples and the range between 2 deviation measures greater and less than the mean represents 95% of the samples. 7. Compare the means for the two groups. Does the pattern of mean differences match your predictions from question #4? The mean of the control group is 27.7826, where as the mean of the experimental group is 33.0455. The preliminary prediction of a happy face positively effecting the tip amount matches the pattern presented by the mean comparison. 8. Write null and alternate hypotheses. If you decided to perform a one-tailed test, be sure to specify which of the two groups you predict will be higher/lower. Null hypothesis: Customers who receive a happy face on their check will leave a similar or equal tip amount to customers who do not receive a happy face on their check. Alternate hypothesis: Customers who receive a happy face will leave a greater tip amount (percentage) than customers who do not receive a happy face on their check.
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