# Statistics Exercise | Example 1 | The Answer

We solve previous statistics exercises

Solution:

1. Representing the table with a scatterplot Mi(xi;yiin a perpendicular coordinate system with origin o' (30;11) and a scale of 1 cm for every 5 years on the axis of abscissa and 2 cm on the axis of ordinates.

2. a)
Assigning the coordinates of point G as the center of the scatterplot.

We have point G (x̄;ȳ), where:

And from it: G(50;13)

b) Representation of point G in the previous chart. (represented in the diagram above)

3. Finding the equation of the least squares regression line: y=ax+b, a and b are given rounded to 10-2.
The regression line equation has the form y=ax+b, where:

To calculate a, we use the following table:

a=(45937)(50×13)7007=(45937)(650)100

a ≃0.06

And we have: b= ȳ-ax̄ =13-0.06(50)=10
Then: y=0.06x+10

4) Plot this line in the previous coordinate system. (represented in the diagram above)

5) We haveThe man is 70 years old then:  x=70
When substituting in the equation of a straight line, we find:
y=0.06 (70)+10=14.2
Since 14.2 ≠ 15.2 Therefore, this is unreasonable according to this modification.