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

What is the cost per ounce of detergent, A 64-ounce bottle of detergent cos...

A 64-ounce bottle of detergent costs $3.20. What is the cost per ounce of detergent? To ?nd out the cost per ounce, divide the cost through the number of ounces; $3.20 ÷ 64 =

Algebra ii, How do you graph a hyperbola?

How do you graph a hyperbola?

Root of function, Root of function: All throughout a calculus course we wi...

Root of function: All throughout a calculus course we will be determining roots of functions. A root of function is number for which the function is zero. In other terms, determ

Set builder notation, For inequalities we contain a similar notation. Base...

For inequalities we contain a similar notation. Based on the complexity of the inequality the solution set might be a single number or it might be a range of numbers. If it is jus

Find the values of k, If the vertices of a triangle are (1, k), (4, -3), (-...

If the vertices of a triangle are (1, k), (4, -3), (-9, 7) and its area is 15 sq units, find the value(s) of k..

find the vector projection - vectors, Given the vectors u = 3 i - 2 j ...

Given the vectors u = 3 i - 2 j + k , v = i + 2 j - 4 k , w = -2 i + 4 j - 5 k use vector methods to answer the following: (a) Prove u , v and w can form

Define ab for given matrix, Define AB where: A = | 3 -...

Define A*B where: A = | 3 -3 6 | B = | 6 1 | | 0 4 2 | | 0 -5 |

Rounding decimals, how can i round decimals

how can i round decimals

Integration, Integration We have, so far, seen that differential ...

Integration We have, so far, seen that differential calculus measures the rate of change of functions. Differentiation is the process of finding the derivative

Power series - sequences and series, Power Series We have spent quite...

Power Series We have spent quite a bit of time talking about series now and along with just only a couple of exceptions we've spent most of that time talking about how to fin

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages