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

Multiply 3 (x + 4) = 3x + 12 to find out the total perimeter, Jake required...

Jake required to find out the perimeter of an equilateral triangle whose sides measure x + 4 cm each. Jake realized that he could multiply 3 (x + 4) = 3x + 12 to find out the total

Statistics, if the sum of mean and variance of a binomial distribution is ...

if the sum of mean and variance of a binomial distribution is 4.8 for five trials, the distribution

Financial Math, can you help me with financial math??

can you help me with financial math??

.fractions, what is the difference between North America''s part of the tot...

what is the difference between North America''s part of the total population and Africa''s part

Reduce the rational expression to lowest terms, Reduce the following ration...

Reduce the following rational expression to lowest terms. x 2 - 2 x - 8/ x 2 - 9 x + 20 Solution When reducing a rational expressio

Solving problems using order of operations, #question.

#question.

Show that p ( x ) = 2 x3 - 5x2 -10 x + 5 intermediate value , Example Sh...

Example Show that p ( x ) = 2 x 3 - 5x 2 -10 x + 5 has a root somewhere in the interval [-1,2]. Solution What we're actually asking here is whether or not the function wi

Prove that r is an equivalence relation, 1. Let S be the set of all nonzero...

1. Let S be the set of all nonzero real numbers. That is, S = R - {0}. Consider the relation R on S given by xRy iff xy > 0. (a) Prove that R is an equivalence relation on S, an

How to calculate arithmetic average or mean, Q. How to calculate arithmetic...

Q. How to calculate arithmetic average or mean? Ans. When people collect information, or data, they can easily be overwhelmed with information. Just imagine listing the b

Geometry of convex sets, (a) Given a norm jj jj on Rn, express the closed b...

(a) Given a norm jj jj on Rn, express the closed ball in Rn of radius r with center c as a set. (b) Given a set A and a vector v, all contained in Rn, express the translate of A by

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages