STAT 1031 Biostatistics HW5 QUESTIONS WITH VERIFIED ANSWERS

20 BME 3060: Introduction to Biostatistics
Homework #5


Download the data ‘studentdata’ from the package ‘LearnBayes.’

1. Create a separate column labelled as ‘HoursSlept’ in the ‘studentdata’ folder recording
how many hours each student slept the previous night. Obtain summary statistics of all
data in the enhanced ‘studentdata.’ 3 points
Code:
library(LearnBayes)
data("studentdata")
studentdata$HoursSlept= (studentdata$WakeUp- studentdata$ToSleep)
dim(studentdata)
head(studentdata)




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summary(studentdata)




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Summary statistics:




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Student Height
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Gender Shoes
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Min. : 1 Min. :54.0 female:435 Min. : 0.00
1st Qu.:165 1st Qu.:64.0 male :222 1st Qu.: 6.00
Median :329 Median :66.0 Median : 12.00
Mean :329 Mean :66.7 Mean : 15.42
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3rd Qu.:493 3rd Qu.:70.0 3rd Qu.: 20.00
Max. :657 Max. :84.0 Max. :164.00
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NA's :10 NA's :22
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Number Dvds ToSleep WakeUp
Min. : 1.00 Min. : 0.00 Min. :-2.500 Min. : 1.000
1st Qu.: 4.00 1st Qu.: 10.00 1st Qu.: 0.000 1st Qu.: 7.500
Median : 6.00 Median : 20.00 Median : 1.000 Median : 8.500
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Mean : 5.67 Mean : 30.93 Mean : 1.001 Mean : 8.383
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3rd Qu.: 7.00 3rd Qu.: 30.00 3rd Qu.: 2.000 3rd Qu.: 9.000
Max. :10.00 Max. :1000.00 Max. : 6.000 Max. :13.000
NA's :2 NA's :16 NA's :3 NA's :2
Haircut Job Drink HoursSlept
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Min. : 0.00 Min. : 0.00 milk :113 Min. : 2.500
1st Qu.: 10.00 1st Qu.: 0.00 pop :178 1st Qu.: 6.500
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Median : 16.00 Median :10.50 water:355 Median : 7.500
Mean : 25.91 Mean :11.45 NA's : 11 Mean : 7.385
3rd Qu.: 30.00 3rd Qu.:17.50 3rd Qu.: 8.500
Max. :180.00 Max. :80.00 Max. :12.500
NA's :20 NA's :32 NA's :4
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This study source was downloaded by 100000784424693 from CourseHero.com on 06-20-2021 21:46:31 GMT -05:00


https://www.coursehero.com/file/80103099/Biostatistics-HW5docx/

, Segregate the ‘studentdata’ by gender.

2. Obtain summary statistics of ‘Height’ for males. 2 points
Code:
males_data= subset(studentdata, studentdata$Gender=="male") #separate male data from
female
summary(males_data$Height)

Summary statistics of height for males




3. Obtain standard deviation of ‘Height’ for males. 1 point




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Code: sd(males_data$Height, na.rm = T)




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Standard deviation of ‘Height’ for males: 3.080943 (units)




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4. Obtain summary statistics of ‘Height’ for females. 2 points
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Code: females_data= subset(studentdata, studentdata$Gender=="female")Summary
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statistics of ‘Height’ for females:
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5. Obtain standard deviation of ‘Height’ for females. 1 point
Code: sd(females_data$Height, na.rm = T)
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Standard deviation of ‘Height’ for females: 3.363986
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6. Portray the (density) histograms of heights for males and females in the same frame.
Superimpose each histogram with nonparametric density curve and appropriate normal
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curve. Include the rugs. 6+4+4+2 points
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Code:
par(mfrow= c(1,2), oma= c(5, 4, 4, 2))

hist(males_data$Height, xlab= "Height of Males",
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ylab= "Density", density= 15, freq=F, col= "black",
main= "Density Histogram + Nonparametric Curve+ Normal Curve")

lines(density(x= males_data$Height, na.rm = T), col= "blue", lwd=2)
curve(dnorm(x, mean= 70.51, sd= 3.080943 ), col= "red", lwd= 2, add=T)


This study source was downloaded by 100000784424693 from CourseHero.com on 06-20-2021 21:46:31 GMT -05:00


https://www.coursehero.com/file/80103099/Biostatistics-HW5docx/