assignment 5 q1

HYPOTHESES

QUESTION

What are the null and alternate hypotheses for your research?

H0:There is no relationship between time spent (minutes) in the shop and number of drinks purchased

H1:There is a relationship between time spent (minutes) in the shop and number of drinks purchased

library(readxl)

A5RQ1 <- read_excel("C:\\Users\\kuppi\\OneDrive\\Desktop\\A5RQ1.xlsx")

library(psych)

describe(A5RQ1[, c("Minutes", "Drinks")])

##         vars   n  mean    sd median trimmed   mad min   max range skew kurtosis
## Minutes    1 461 29.89 18.63   24.4   26.99 15.12  10 154.2 144.2 1.79     5.20
## Drinks     2 461  3.00  1.95    3.0    2.75  1.48   0  17.0  17.0 1.78     6.46
##           se
## Minutes 0.87
## Drinks  0.09

hist(A5RQ1$Minutes,
     main = "Histogram of V1",
     xlab = "Value",
     ylab = "Frequency",
     col = "lightblue",
     border = "black",
     breaks = 20)

hist(A5RQ1$Drinks,
     main = "Histogram of V2",
     xlab = "Value",
     ylab = "Frequency",
     col = "lightgreen",
     border = "black",
     breaks = 20)

QUESTION

Q1) Check the SKEWNESS of the VARIABLE 1 histogram. In your opinion, does the histogram look symmetrical, positively skewed, or negatively skewed?

1. Variable 1 is positively skewed. majority of the values lie on the left with the tail on the right

Q2) Check the KURTOSIS of the VARIABLE 1 histogram. In your opinion, does the histogram look too flat, too tall, or does it have a proper bell curve?

1. Variable 1 is too tall. the peak is sharp, not like a normal bell shape,the values are closer at the tail

Q3) Check the SKEWNESS of the VARIABLE 2 histogram. In your opinion, does the histogram look symmetrical, positively skewed, or negatively skewed?

1. Variable 2 is positively skewed. majority of the values lie on the left with the tail on the right

Q4) Check the KUROTSIS of the VARIABLE 2 histogram. In your opinion, does the histogram look too flat, too tall, or does it have a proper bell curve?

1. Variable 2 is too tall. The peak is high and not wide like a normal curve

shapiro.test(A5RQ1$Minutes)

## 
##  Shapiro-Wilk normality test
## 
## data:  A5RQ1$Minutes
## W = 0.84706, p-value < 2.2e-16

shapiro.test(A5RQ1$Drinks)

## 
##  Shapiro-Wilk normality test
## 
## data:  A5RQ1$Drinks
## W = 0.85487, p-value < 2.2e-16

QUESTION

Was the data normally distributed for Variable 1?

No, because p < 0.05

Was the data normally distributed for Variable 2?

No, because p < 0.05

library(ggplot2)

## 
## Attaching package: 'ggplot2'

## The following objects are masked from 'package:psych':
## 
##     %+%, alpha

library(ggpubr)

ggscatter(A5RQ1, x = "Minutes", y = "Drinks",
          add = "reg.line",
          conf.int = TRUE,
          cor.coef = TRUE,
          cor.method = "spearman",
          xlab = "Variable Minutes", ylab = "Variable Drinks")

QUESTION

17. Is the relationship positive (line pointing up), negative (line pointing down), or is there no relationship (line is flat)?

18. the relationship is positive

cor.test(A5RQ1$Minutes, A5RQ1$Drinks, method = "spearman")

## Warning in cor.test.default(A5RQ1$Minutes, A5RQ1$Drinks, method = "spearman"):
## Cannot compute exact p-value with ties

## 
##  Spearman's rank correlation rho
## 
## data:  A5RQ1$Minutes and A5RQ1$Drinks
## S = 1305608, p-value < 2.2e-16
## alternative hypothesis: true rho is not equal to 0
## sample estimates:
##       rho 
## 0.9200417

1. WRITE THE REPORT

Q1) What is the direction of the effect?

1. positive correlation beacuse the rho value is 0.9200417 which is positive

Q2) What is the size of the effect?

1. The size of effect is “strong” since the rho value is 0.9200417 which is ± 0.50 to 1.00

Summary

A Spearman correlation was conducted to assess the relationship between Minutes and Drinks (n = 461).There was a statistically significant correlation between stress (M = 29.89, SD = 18.63) and sleep quality (M = 3.00, SD = 1.95).The correlation was positive and strong, ρ(459) = 0.9200417, p < 2.2e-16.As the number of Minutes increases, the number of drinks purchased decreases.