https://www.econometrics-with-r.org/3.3-hypothesis-tests-concerning-the-population-mean.html#one-sided-alternatives


for hypothesis testing 

install.packages("tseries")
install.packages("forecast")
install.pakages("fpp")
install.pakages("ggplot2")
library(forecast)
library(tseries)
library("ggplot2")
x <- rnorm(1000) # no unit-root
adf.test(x)

# Output to be created as png file 
png(file = "TimeSeriesGFG.png") 
  
# Plotting graph without forecasting 
plot(BJsales, main = "Graph without forecasting", 
col.main = "darkgreen") 
  
# Saving the file 
dev.off() 
  
# Output to be created as png file  
png(file = "TimeSeriesARIMAGFG.png")

# Fitting model using arima model #  
> fit <- auto.arima(BJsales)
> fit

# Next 10 forecasted values  
forecastedValues <- forecast(fit, 10) 

# forecasted values 
print(forecastedValues) 

plot(forecastedValues, main = "Graph with forecasting", 
col.main = "darkgreen") 

# saving the file   
dev.off()