(11) Consider the following data 12 50 24 70 95 123 89 67 A second-year student in Statistics stated that there is no evidence that these data can be classified as time series data What is the reason of his/her statement? (2) (12) Consider the daily mean temperatures (in degrees Celsius) for a given city during the seven days of last week 12 13 16 2 10 14 15 Why these data can be classified as time series data? (2) (13) Some people argue that, in South Africa, the price of food has been increasing during the last 15 years, and the rate of employment has been decreasing during the same period Give the time series concept being referred to in such a statement (2) (14) Define (a) seasonal variations and (b) cyclical variations, then give the main difference between the two concepts in time serics (15) Define irregular variations in time series and give three examples (6) (5)