STAT20029 (T2,2020) Questions

Week 12, Refer Chapter 15

Practice Problem 15.1

PP15-1: Use the following time-series data to answer the given questions.
(a) Develop forecasts using a 3-period centred moving average.

(b) Develop forecasts for periods 5 to 12 using a 4-period moving average.

Activity 12.1

Activity12-1: The following table provides five consecutive observations of daily discharge in a flashy river. Calculate the centred 3-point moving averages.

Practice Problem 15.3

PP.15.3: Following are time-series data for nine time periods. Use exponential smoothing with constants of 0.3 to forecast time periods 1 to 9.

Activity 12.2

Activity12-2: Using W = 0.2, find the exponentially smoothed values for the following data.

Activity 12.3

Activity12-3: Land tax on a property by the Victorian government for 3 years is given in the table below. Use exponential smoothing with a weighting coefficient of 0.6 to forecast land tax in the year 2020.

Activity 12.4

Activity12-4: Ms Kay wants to invest in properties, but she does not have enough savings to pay for the deposit. To increase her savings she decides to invest in shares. She gains knowledge about the share market using various stock market analysis tools. Then she invests in the Australian Stock Exchange. The values of her portfolio of shares in different years are given in the following table. Use exponential smoothing with a smoothing coefficient (W) of 0.25 to forecast the portfolio value in 2018.

Activity 12.5

Activity12-5: Simple price index of a 2-litre bottle of extra virgin olive oil is given in the table below with 2015 as the base year. What will be the simple price index of 2019 with 2017 as the base year?

Practice Problem 15.22

PP.15.22: Calculate Laspeyres price indices for 2018 from the following data. Use 2010 as the base year.

Activity 12.6

Activity12-6: Prices of four items in years 2005, 2010 and 2015 are given in the table below. Calculate the CPI of 2015 with 2005 as the base year and for all four items using Laspeyres method.

Revision Problem 15.4

RP.15.4: Using the following data and 2006 as the base year, compute the Paasche price index for 2008

Activity 12.6

Activity12-6: American National Safety Council reported that the risk of death from lightning is 1 in 79,746 and the risk of death from a shark attack is 1 in 3,748,067 from recorded observations. Some people use these statistics to argue that we are safer from shark attack than from lightning. Why is this misuse of statistics? (One could use similar approach of misuse of statistics to conclude that space is safer place to live than on earth because only three astronauts ever died there.)