library(readxl)
library(ggpubr)
## Loading required package: ggplot2
A4Q2 <- read_excel("C:\\Users\\Tharu\\Downloads\\A4Q2.xlsx")
ggscatter(
A4Q2,
x = "sleep",
y = "phone",
add = "reg.line",
xlab = "sleep",
ylab = "phone"
)
# The relationship between the two variables is linear. # The
relationship between the two variables is negative. # The relationship
between the two variables is strong. # There are no outliers.
mean(A4Q2$sleep)
## [1] 7.559076
sd(A4Q2$sleep)
## [1] 1.208797
median(A4Q2$sleep)
## [1] 7.524099
mean(A4Q2$phone)
## [1] 3.804609
sd(A4Q2$phone)
## [1] 2.661866
median(A4Q2$sleep)
## [1] 7.524099
hist(A4Q2$sleep,
main = "sleep",
breaks = 20,
col = "lightblue",
border = "white",
cex.main = 1,
cex.axis = 1,
cex.lab = 1)
# Variable 1: Sleep # The first variable looks approximately normally
distributed. # The data is fairly symmetrical around the centre. # The
data shows bell-shaped curve and there are a few values at
lower-end.
hist(A4Q2$phone,
main = "phone",
breaks = 20,
col = "lightcoral",
border = "white",
cex.main = 1,
cex.axis = 1,
cex.lab = 1)
# Variable 2: Phone # The second variable does not appear to be normally
distributed. # The data is not symmetrical and is positively skewed. #
The histogram does not show a clear bell-shaped curve.
shapiro.test(A4Q2$sleep)
##
## Shapiro-Wilk normality test
##
## data: A4Q2$sleep
## W = 0.91407, p-value = 8.964e-08
shapiro.test(A4Q2$phone)
##
## Shapiro-Wilk normality test
##
## data: A4Q2$phone
## W = 0.89755, p-value = 9.641e-09
cor.test(A4Q2$sleep, A4Q2$phone, method = "pearson")
##
## Pearson's product-moment correlation
##
## data: A4Q2$sleep and A4Q2$phone
## t = -11.813, df = 148, p-value < 2.2e-16
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
## -0.7708489 -0.6038001
## sample estimates:
## cor
## -0.6966497
cor.test(A4Q2$sleep, A4Q2$phone, method = "spearman")
##
## Spearman's rank correlation rho
##
## data: A4Q2$sleep and A4Q2$phone
## S = 908390, p-value < 2.2e-16
## alternative hypothesis: true rho is not equal to 0
## sample estimates:
## rho
## -0.6149873