The effect of coffee consumption

Task 4
Data Description
The dataset given here shows the effect of coffee consumption on the test scores of
University students.
Sub setting the Data
Initially the data had 685 records out of which 131 had missing values. For that reason, a
subset is formed by omitting the missing values that contains 554 observations.
Objective of the Study
The main objective is to investigate whether ingestion of coffee has effect on the marks
of University students. To achieve this, at first it is checked if there is any notable variation in
scores due to coffee intakes. Further, the relation between age of a student and test score after
having coffee is also visualized.
Descriptive Statistics
Here Gender is a categorical variable with 1=male and 2=female. A descriptive study is
performed for the rest of the numerical variables (McCormick and Salcedo 2017).

It can be noted that the average age of a stude4nt is 25.62≈26 years. 50% students have
age less than 26 years. Further, 25% students are below 22 years and 25% are above 29 years
(from the percentiles). Highest number of students are 20 years old. The value of skewness show
that the data is positively skewed.
The average mark (55.37 approx. before) is increased after consuming coffee (70.32=70
approx.). From the medians, it can be said that 50% students scored less than 60 in test 1 and 73
that for test 2. In test 1, highest number of students got 62 highset frequency of score is 75 is test
2. Both the variables have negative skewness. Hence, they have distributions skewed to the left.
Normality Test
The normality assumptions are checked using histogram and normal Q-Q plot (Das and
Imon 2016).

The histograms imply that the test 1 scores are approximately normally distributed
irrespective of gender.