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OVER BOOKED?. A Facebook Experiment. Purpose. To test the claim that the average teenager uses Facebook for only 5 hours a week. Sample. Number Assignment + Random Digit Table = SRS. Own Facebook account used. 100 subjects out of 594 friends. Standardized Question. Procedure.
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OVER BOOKED? A Facebook Experiment
Purpose To test the claim that the average teenager uses Facebook for only 5 hours a week
Sample • Number Assignment + Random Digit Table = SRS • Own Facebook account used • 100 subjects out of 594 friends • StandardizedQuestion
Procedure • Empirical data is translated into appropriate graphical displays.
Creating a Hypothesis Facebook.com claims that the average teenager spends five hours a week using Facebook. [Using Facebook means actually using its features and not just having it open]. I believe that a teenager uses Facebook for longer than five hours a week.
What Test? A One Sample Mean T-Test…because the population standard deviation is unknown & a mean ≠ proportion • Conditions: • The distribution is an SRS • Due to the Central Limit Theorem (CLT) the population is normal since n>40
One Sample μ T-Test * Can not sketch critical region/value because p-value is too small
Conclusion A mean of 20 hours would occur .000007% of the time if the population mean is 5 hours. So we can safely reject at the 5% significance level. And conclude that a teenager uses Facebook for more than 5 hours a week!
Confidence Interval I want to estimate the mean time a teenager spends on Facebook a week. Since we do not know , I will use the one sample t-interval. The data was collected via a random experiment. Due to the Central Limit Theorem (CLT) the population is normal since n>40 Confidence Interval = 95%
Confidence Interval Cont. I am 95% confident that the mean time a teenager spends on Facebook a week is between 18.579 to 21.881 hours
Reflection Strengths & Weaknesses… Population Mean is National Standardized Question Overbooked? A Facebook Experiment Unclear What Type of Usage Only My FB Friends Large # of Subjects Inaccurate Answers