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 8^th 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 8^th year sales = 12 + 1.86 (8)

=26.88 that is 26,888 units.

Related Discussions:- Forecasting by using least squares

5-1, how it is

how it is

Example of log rules, Example of Log Rules: Y = ½ gt 2 where g = 32 ...

Example of Log Rules: Y = ½ gt 2 where g = 32 Solution: y = 16 t 2 Find y for t = 10 using logs. log y = log 10 (16 t 2 ) log 10 y = log 10 16 + log 10

Application of operations research, how to write a thesis

how to write a thesis

Partial Differential Equation, Determine the minimum capacity C of a Capaci...

Determine the minimum capacity C of a Capacitor given that: C =(ax/(x-a))+(xy/(y-b))+(yb/(b-y)) given that "a" and "b" are fixed values and "x" and "y" vary independently such th

Derivatives with chain rule, Chain Rule : We've seen many derivatives...

Chain Rule : We've seen many derivatives. However, they have all been functions similar to the following kinds of functions. R ( z ) = √z f (t ) = t 50

Learning, my math skills are keeping me from getting my ged need help in al...

my math skills are keeping me from getting my ged need help in all areas

Polynomials, In arithmetic, we deal with numbers. In contrast to this...

In arithmetic, we deal with numbers. In contrast to this, in algebra, we deal with symbols. These symbols are often represented by lower case alphabets. One of th

How far off shore is the sinking ship, A sinking ship signals to the shore ...

A sinking ship signals to the shore for assistance. Three individuals spot the signal from shore. The ?rst individual is directly perpendicular to the sinking ship and 20 meters in

Logarithmic form and exponential form, Logarithmic form and exponential for...

Logarithmic form and exponential form ; We'll begin with b = 0 , b ≠ 1. Then we have y= log b x is equivalent to x= b y The first one is called

Vector addition, Is it possible to add two vectors of unequal magnitude and...

Is it possible to add two vectors of unequal magnitude and get a resultant of zero?Please explain also. Ans) no it is not possible as .. if the magnitude is diffrent then they c

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages