R Basics

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Problem 1:

  1. From set = {1.5, 15, 0, 54, 23}, pick two numbers and perform the Following Operations:
a <- 1.5
b <- 15

#.Subtraction
a-b
## [1] -13.5
sum(1.5, - 15)
## [1] -13.5
#.Multiplication
a*b
## [1] 22.5
sum(15 * 0)
## [1] 0
#.square root
sqrt(b)
## [1] 3.872983
sqrt(54)
## [1] 7.348469

Problem 2

Suppose you have a set of numbers representing the assignments scores:

scores <- c(87,100, 91, 95, 81.5, 0, 39, 74, 92)

#Calculate the average of the scores, and round your answer to two decimal number
mean(scores)
## [1] 73.27778
#Find the Maximum and Minimum score
max(scores)
## [1] 100
#Find how many scores were above the average, use coding for this
+mean(scores)
## [1] 73.27778
#Create a new set called new_scores that includes the elements from indices 2 to 6 of the scores vector
new_scores <- c(2, 4, 5, 6)

new_scores[2:6]
## [1]  4  5  6 NA NA

Problem 3:

Read section 2.3, then answer the following questions

# Create a vector with the number 1 repeated 5 times. Print it
my_seq <- c(1,2,3,4,5,6,7,8,9,10)
my_seq <- rep(1, times= 5)

# Create a vector with a sequence of numbers from 1 to 10 with a step of 2. Print it

my_sep <- c(1,2,3,4,5,6,7,8,9,10)
my_sep <- c(2,4,6,8,10)

# Create a vector by repeating a sequence from 1 to 3, 2 times. Print it.

my_soda <- c(1,2,3)
a <- 1
b <-2
c <-3

rep(a:c, times = 2)
## [1] 1 2 3 1 2 3
#### Problem 4
mixed_vector <- c(1, "two", 3.0, TRUE, 2)

# Check the class of the vector
class(mixed_vector)
## [1] "character"
## Coerce to numeric and print it 
as.numeric(mixed_vector)
## Warning: NAs introduced by coercion
## [1]  1 NA  3 NA  2