Sleep in Mammals

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The data is concerned with sleep in mammals. The data set has 62 observations and nine predictor variables. The data takes into account the effects of environmental and ecological factors on the sleep cycles of different mammals. In this study the total hours of sleep a mammal gets each day is the response variable, Y. The predictor variables X1, X2, X3, X4, X5, X6, X7, X8 and X9 are related to body weight, brain weight, slow wave sleep, paradoxical sleep, maximum life span, gestation time, predation index, sleep exposure index, and overall danger index, respectively. The data was collected by Dr. Truett Allison in 1976. The data was used by Dr. Truett Allison in the article, “Sleep in Mammals: Ecological and Constitutional Correlates.” (Science, 732-734). The data was found on the Carnegie Melon Website. ( The purpose of this project is to determine whether there is a correlation between the predictor variable and the total hours a mammal sleeps per day, and to find a model that best fits the data. Variable Variable Name Y Total Sleep (hours/day) X1 Body Weight (kilograms) X2 Brain Weight (grams) X3 Slow Wave (‘Non-Dreaming”) Sleep (hours/day) X4 Paradoxical (“Dreaming”) Sleep (hours/day) X5 Maximum Life Span (years) X6 Gestation Time (days) X7 Predation Index (1-5) 1=least likely to be preyed upon 5=most likely to be preyed upon X8 Sleep Exposure Index (1-5) 1=least exposed while sleeping 5=most exposed while sleeping X9 Overall Danger Index (1-5) 1=least danger from other animals 5=most danger from other animals Due to missing values, 20 observations were removed from the data set. Also, two strong outliers, the Asian elephant and man, were removed from the data. The remaining 40 observations were used to create the full model of the data. The full
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