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A correlation study of Age vs. Hours of Sleep. MATH -2040 TERM PROJECT-SPRING 2014. Luciene Barbosa, Cely Carol Bueno & Saradha Rajamani. Sample Collection. Aim: Find linear relationship (if exist) between age and hours of sleep using correlation coefficient, r.
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A correlation study of Age vs. Hours of Sleep MATH-2040 TERM PROJECT-SPRING 2014. Luciene Barbosa, Cely Carol Bueno& Saradha Rajamani
Sample Collection • Aim: Find linear relationship (if exist) between age and hours of sleep using correlation coefficient, r. • Data is gathered from friends and family. • Data gathered from 76 individuals. • Data collection questionnaire: • What is your age? Please indicate your age in years and months. • How many hours do you sleep every day? Please indicate the average hours of sleep you typically get every day.
Data Analysis Scheme • Statistics • Mean, median, mode • SD, range, Q1 and Q3 • Outliers • 1.5x IQR • Two SD above the mean • Frequency histogram of Age and Hours of Sleep • Correlation using r
Statistics • Outliers • Two SD above mean • Age – 73. • Hours of Sleep – 3.5, 4, 4, 10 & 10. • 1.5x IQR – no outliers
Correlation Coefficient r = -.103 r*.05 = .235 for 70 samples. r (w/o 3.5,4,10) = -0.162
Residual Plot Constant error variance – independent variable predicting residuals
Conclusion • Challenges • Equal representation of all age groups. • Data not obtained from minors, which could have changed the linear relationship. • Interpretation • No evidence of linear relationship between Age and Hours of sleep in this sample set. • Sample set does not represent population. • Sampling (convenient sampling) not randomized. • No linear correlation between the two variables in population.