Forecasting by using least squares, Mathematics

Assignment Help:

Forecasting By Using Least Squares

Data have been kept of sales over the last seven years

Year

1

2

3

4

5

6

7

Sales (in '000 units

14

17

15

23

18

22

27

It is required to forecast the sales for the 8th year

Solution

Years (x)

Sales (y)

xy

x2

1

14

14

1

2

17

34

4

3

15

45

9

4

23

92

16

5

18

90

25

6

22

132

36

7

27

189

49

       Σx=28

     Σy = 136

       Σxy=596

    Σx2= 140

136 = 7a + 28b

596 = 28a + 140b

∴b = 1.86

And substituting in one of the equations we acquire

a = 12

∴ Regression line = y = 12 + 1.86x

Or, Sales in ('000s of units) = 12.00 + 1.86 (no of years)

We utilize this expression for forecasting, for 8th year sales = 12 + 1.86 (8)

=26.88 that is 26,888 units.


Related Discussions:- Forecasting by using least squares

Volumes of solids of revolution - method of rings, Volumes of Solids of Rev...

Volumes of Solids of Revolution / Method of Rings In this section we will begin looking at the volume of solid of revolution. We have to first describe just what a solid of rev

Cubic math, A fish tank has the base area of 45 cm3 and is filled to the de...

A fish tank has the base area of 45 cm3 and is filled to the depth of 12 cm.If the height is 25 cm then how much more will be needed to fill the rest of the tank?

Linear equation, The sum of the digit number is 7. If the digits are revers...

The sum of the digit number is 7. If the digits are reversed , the number formed is less than the original number. find the number

Trigonometric approximation grid, With a compass draw the arc associated wi...

With a compass draw the arc associated with a 720° angle, it looks like a circle. With a protractor, label the angle in multiples of 45° and 30° up to 720°.  Notice 30° and 390° ar

Find the shortest paths in the digraph, 1. a) Find the shortest paths from ...

1. a) Find the shortest paths from r to all other nodes in the digraph G=(V,E) shown below using the Bellman-Ford algorithm (as taught in class).  Please show your work, and draw t

Solve the linear equation, Solve the linear equation: The equation rel...

Solve the linear equation: The equation relating the pressure that is denoted by P, to the force, F & the area, A, over which the force is applied is P =F/A.  Solve this equat

Estimation of difference among population proportions , Estimation of diffe...

Estimation of difference among population proportions Assume the two proportions be described by P1 and P2, respectively,Then the difference absolute between the two proportion

Square numbers, determine the square of the following numbers ... a.8 b.13 ...

determine the square of the following numbers ... a.8 b.13 c.17 and d.80

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd