Homework 1 - Exercise 2.1

library(fpp3)
library(dplyr)
library(tsibble)
library(lubridate)

1) Simple annual tsibble

y <- tsibble(
  Year = 2015:2019,
  Observation = c(123, 39, 78, 52, 110),
  index = Year
)
y

## # A tsibble: 5 x 2 [1Y]
##    Year Observation
##   <int>       <dbl>
## 1  2015         123
## 2  2016          39
## 3  2017          78
## 4  2018          52
## 5  2019         110