Question

Write code in R or Rstudio (Programming)

You track your commute times for three weeks (15 days), recording the following times in minutes: 17, 16, 20, 24, 22, 15, 21, 25, 17, 90, 16, 17, 22, 20, 20. Enter the data into a 3-by-5 matrix, where rows are weeks and columns are weekdays. Please answer the following questions and provide the necessary code. (a) Name each column with the weekday abbreviations, i.e., Mon, Tue, Wed, Thu, and Fri (b) Find the shortest, the longest, the average, and the median commute time within those three weeks. (c) The 90 was a mistake. It should have been 19. How can you fix this? Do so, and then find the new average and median. (d) How many times was your commute 20 minutes or more? (e) What percent of your commutes are less than 18 minutes long? (f) In average, which weekday you spend the most commute time? 1 (g) In average, which weekday you spend the least commute time? (h) Summarize the matrix into a vector where each entry is the average commute time for the corresponding weekday in those three weeks. Find the differences from day to day. Are there any weekday where the amount dropped from the previous weekday?

Answer 1

times = matrix(
c(17,16,20,24,22,15,21,25,17,90,16,17,22,20,20),
nrow = 3,
ncol = 5,
byrow = TRUE)

#a
weekdays <- c("Mon","Tue","Wed","Thu","Fri")
colnames(times)<-weekdays
print(times)

#b
print(min(times))#shortest
print(max(times))#longest
print(mean(times))#average
print(median(times))#median

#c
times[2,5] = 19
print(mean(times))#new average
print(median(times))#new median

#d
minutes20=0
for(i in times) {

        if( i>=20){
           minutes20 = minutes20 + 1
       }
}
print(minutes20)

#e
minutes18=0
for(i in times) {

        if( i<18){
           minutes18 = minutes18 + 1
       }
}
percent18=minutes18*100/15
print(percent18)

#f
A=colMeans(times)
print(names(A[A==max(A)]))

#g
A=colMeans(times)
print(names(A[A==min(A)]))

#h
AverageCommune=colMeans(times)
Difference=diff(AverageCommune)
print(Difference)

weekDayDrop = names(Difference[Difference<0])
print(weekDayDrop)