AE 311 PRELIM EXAM PART II:

The sample data below shows the total number of automobile sales (in thousands) in the Philippines for the last 20 years.

Data: 90, 85, 80, 95, 103, 110, 115, 103, 105, 98, 93, 82, 82, 85, 90, 90, 110, 110, 115, 95.

Entering the data manually into RStudio, present a complete R script that would provide each of the following: a. Stem-and-leaf plot b. Dot plot c. Mean number of automobiles sold per year d. Median number of automobiles sold per year

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library(pander)
library(ggplot2)
sales <- c(90, 85, 80, 95, 103, 110, 115, 103, 105, 98, 93, 82, 82, 85, 90, 90, 110, 110, 115, 95)

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  1. For the stem-and-leaf plot:
stem(sales)
  
    The decimal point is 1 digit(s) to the right of the |
  
     8 | 02255
     9 | 0003558
    10 | 335
    11 | 00055

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  1. For the dot plot:
ID <- 1:20
data <- data.frame(ID, sales)
ggplot(data, aes(sales)) + geom_dotplot(binwidth = 1.2)

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  1. For the mean number of automobiles sold per year:
x1 <- mean(sales)
pander(round(x1, digits = 2))

96.8

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  1. For the median number of automobiles sold per year:
x2 <- median(sales)
pander(round(x2, digits = 2))

95