Q.10.23(a) For the data Years 1990 1991 1992 1993 1994 1995 1996 1997 Y 557.5 732.4 713.9 763.7 770.9 901.1 901.5 1007.2 Fit a straight line and find the trend value. (b) The following are the quarterly index numbers of whole- sales prices. Years 1928 1929 1930 1931 1932 Quarterly index | 125 114 99 80 80 Fit a linear trend to these data and add the trend to the original chart. Q.10.24 (a) For the following time-series, determine the trend by using the method of (i) three-year moving averages, and (ii) least squares for fitting a straight line. Years 1970 1971 1972 1973 1974 1975 1976 1977 1978 Values 12 23 37 48 41 37 48 61 70 Which trend do you prefer, and why? (b) Measure trend of following time series by least squares method taking 1990 as origin. Years 1990 1991 1992 1993 1994 1995 Values 7 15 21 26 33 40 Q.10.25 (a) If the straight line fitted to the data for the year 1968 to 1975 both inclusive with origin at the middle of 1971 and 1972 is Y = 7.67 + 6.43X the unit of X being one year, then find out the trend values for the year 1968 to 1975. (b) Fit a trend line by the method of least squares to data. Years 1990 1991 1992 1993 1994 1995 1996 Production(000mds) 40 45 46 42 47 50 46