Assignment 6

library(readr)
library(plotly)

## Loading required package: ggplot2

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## Attaching package: 'plotly'

## The following object is masked from 'package:ggplot2':
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## The following object is masked from 'package:stats':
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## The following object is masked from 'package:graphics':
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library(dplyr)

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## Attaching package: 'dplyr'

## The following objects are masked from 'package:stats':
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## The following objects are masked from 'package:base':
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hr <- read_csv('https://raw.githubusercontent.com/aiplanethub/Datasets/refs/heads/master/HR_comma_sep.csv')

## Rows: 14999 Columns: 10

## ── Column specification ────────────────────────────────────────────────────────
## Delimiter: ","
## chr (2): Department, salary
## dbl (8): satisfaction_level, last_evaluation, number_project, average_montly...
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## ℹ Use `spec()` to retrieve the full column specification for this data.
## ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.

1. Histogram: Distribution of Employee Satisfaction
   Create a histogram of the satisfaction_level variable.
   The title should reflect a key takeaway from the distribution.

plot_ly(hr, x = ~satisfaction_level, type = "histogram") %>%
  layout(title = "Most Employees are Satisfied (Satisfaction > .5)",
         xaxis = list(title = "Satisfaction Level"),
         yaxis = list(title = "Number of Employees"))

Most Employees are Satisfied (Satisfaction > .5)
About 6% of employees are extremely dissastisfied (Satisfaction <= .1)

2. Box Plot: Last Evaluation Scores
   Create a box plot of the last_evaluation variable.
   The title should highlight an important insight about the evaluation scores.

plot_ly(hr, x = ~last_evaluation, type = "box") %>%
  layout(title = "Last Evaluation Scores are Between 0.56 and 0.87",
         xaxis = list(title = "Last Evaluation Score"),
         yaxis = list(title = "Number of Evaluations"))

The median last evaluation score was a 0.72
The middle 50% of the data from number of evaluations had last evaluation scores between 0.56 and 0.87

3. Comparative Box Plot: Monthly Hours by Department
   Create a comparative box plot of average_montly_hours grouped by department.
   The title should emphasize a significant difference or pattern among departments.

plot_ly(hr, x = ~Department, y = ~average_montly_hours, type = "box") %>%
  layout(title = "The Median Average Monthly Hours of Employees are >= 197, maximum 204",
         xaxis = list(title = "Department"),
         yaxis = list(title = "Average Monthly Hours"))

The Management department has the highest median average monthly hours of 204
The HR department has the lowest median average monthly hours of 197

4. Pie Chart of Frequencies: Attrition by Salary Level
   Create a pie chart showing the frequency of employee attrition (left) for each salary category.
   The title should point out the relationship between salary and attrition.

salary <- hr %>% 
  filter(left == 1) %>% 
  count(salary)

plot_ly(salary, labels = ~salary, values = ~n, type = 'pie') %>%
  layout(title = 'People Who Receive a Low Salary are Most Likely to Leave their Jobs')

2.3% of people who receive a high salary are likely to leave their job
36.9% of people who receive a medium salary are likely to leave their job
60.8% of people who receive a low salary are likely to leave their job, so this group of people is most likely to leave their job

5. Bar Plot of Averages: Average Satisfaction by Department
   Create a bar plot displaying the average satisfaction_level for each department.
   The title should highlight a key observation about departmental satisfaction.

satisfaction_level <- hr %>%
  group_by(Department) %>%
  summarise(satisfaction_level = mean(satisfaction_level, na.rm = TRUE))

plot_ly(satisfaction_level, x = ~factor(Department), y = 
~satisfaction_level, type = 'bar') %>%
  layout(title = 'The Management Department has the Greatest Satisfaction Level of <0.62',
         xaxis = list(title = 'Department'),
         yaxis = list(title = 'Average Satisfaction Level'))

The Accounting department has lowest satisfaction level of 0.58
The HR department has the second lowest satisfaction level of 0.59