Regression

BSCA1 Practical 18:

This week’s Task: (40 Marks)

This week we’re going to write an application to carry out Simple Linear Regression!!
You must get this practical signed off before you leave today.

Note: Simple Linear Regression is a statistical procedure for finding the best-fit line
through a series of x, y points in order to establish a mathematical relationship
between the quantities for the purposes of prediction.

In order to do this, values are entered in x, y pairs (assuming a causal relationship
holds between the quantities) and values for the slope of the line (m) and the y-axis
intercept (c) are determined as follows:

n xy   x y
 y
x

m 
and c 
 m

n x   x2
2

n
n

Note: n is the number of data (x,y) pairs




After the data has been entered, the Find Best-Fit button outputs the equation of the
regression line and the allows a prediction for Y to be obtained by entering a value for
X

Test your program with the following data:

X
5
10
15
20
30
30
30
50
50
60
Y
190
240
250
300
310
335
300
300
350
395

Regression line: Y = 2.8033 X + 212.90

When X = 40, the prediction for Y is 325

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