Q.4. The data are given below. For the 2015, replace their sales with the last two digits of your registration number. (a). Fit a trend line to the following data by graphical method. (b). Draw a...

Extracted text: Q.4. The data are given below. For the 2015, replace their sales with the last two digits of your registration number. (a). Fit a trend line to the following data by graphical method. (b). Draw a trend line by the method of semi-averages. (c). Calculate the trend value to the following data by the method of moving- averages. Interpret the part (a), (b) and (c) results and generalize your conclusion. Year 2015 2016 2017 2018 2019 2020 Sales (in Rs, 000) 99 73 79 75 82 85