Data Visualization

[gizemdgn]

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Question

Gr2-Grades.xlsx

As we remember, there was the midterm exam in 14th November. Unfortunately some students, including me :( , get score under the average of the group 2 class. To see the results, write a code in ggplot and determine how many students get score under the average for midterm. Also the first quiz scores should be indicated on the same plot. (The file is loaded as an excel file above the question, please download it at first). Output must be like these;

library(ggplot2)
library(dplyr)
library(readxl)
Gr2_Grades <- read_excel("Gr2-Grades.xlsx")
MeanGrades <- mean(Gr2_Grades$Midterm1)
Gr2_Grades %>%
  group_by(StudentNo) %>%
  summarise(ave_Midterm1 = mean(Midterm1,na.rm = TRUE),
         ave_Quiz1 = mean(Quiz1,na.rm = TRUE)) %>%
  ggplot() +
  geom_point(aes(x=StudentNo ,y=ave_Midterm1 , col="Midterm1")) +   
  geom_point(aes(x=StudentNo ,y=ave_Quiz1 , col="Quiz1")) +
  geom_hline(yintercept = MeanGrades, colour = "white", size = 3) +
  coord_flip()
Gr2_Grades %>%
  filter(Midterm1<MeanGrades) %>%
  count()

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[alperyilmaz]

I think we talked about this during class, read_excel("C:/Users/perfe/Desktop/x/Gr2-Grades.xlsx") is a big NO NO!

The data for the question should be accessible by others.

[gizemdgn]

The excel file is loaded on the question, I just edited it. Sorry for the mistake.

[alperyilmaz]

some issues:

• I suppose you forgot to include the answer for calculating the average, how did you get 40.56 in filter(Midterm1<40.56)
• thanks for uploading the data, please update the read_excel() command as read_excel("Gr2-Grades.xlsx") so that anybody who is copy/pasting this code can run it smoothly
• please include the necessary libraries in solution. which package does user need to load for read_excel?

[gizemdgn]

I updated the question. Thank you for your helping.