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Forecast Panchakanya sales for 2020

Short answer

Fit linear trend Y = 632.857 + 43.393X (origin 2004). For 2020, X = 16, forecast sales = 632.857 + 43.393 × 16 = Rs 1,327.1 million.

Panchakanya has recorded the sales of its products in different years as below. Forecast the sales for year 2020.

Year2001200220032004200520062007
Sales (Rs. in Million)500550575675650700780

Method

Sales are growing roughly in a straight line, so fit a linear trend Y = a + bX by least squares. Take 2004 (middle year) as the origin: X = year − 2004. Then ΣX = 0, a = ΣY/n, b = ΣXY/ΣX².

YearXY (Rs million)XYX²
2001−3500−1,5009
2002−2550−1,1004
2003−1575−5751
2004067500
200516506501
200627001,4004
200737802,3409
Total04,4301,21528

a = 4,430 / 7 = 632.857 b = 1,215 / 28 = 43.393

Trend equation: Y = 632.857 + 43.393 X

Forecast for 2020

X = 2020 − 2004 = 16 Y = 632.857 + 43.393 × 16 = 632.857 + 694.286 = 1,327.1

Answer: Forecast sales for 2020 = about Rs 1,327 million. (Sales grow by about Rs 43.4 million a year. The forecast is 13 years beyond the data, so it is only indicative.)

✓ Answer checked by Claude Opus 5.5 (high effort)

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