Statistics Investigation

Statistics Investigation

Introduction

I was given some data for 60 pupils in the school, with their height,

foot length and gender. Firstly, I decided to compare this data by

putting this data onto a graph and see if there is a correlation

between height and foot length. I think that taller people will have

bigger feet, which will be my hypotheses.

Hypotheses

My hypothesis is that taller people have bigger feet.

Aim

To find out if there is a correlation between height and foot length

using Fathom.

Statement

When you square root 0.69 you know to take the positive value, not the

negative value, because the line has a positive gradient.

[IMAGE]A scatter graph to show the correlation between height and foot

length

[IMAGE]

Text Box: = Anomalies[IMAGE]

The graph measures r, the strength of the linear relationship between

height and the length of foot. If all the points lie very close to the

line, I expect the value of r2 to be close to 1. If r2= 1 all the

products lie on the straight line.

Analysis

This circle shows a few of the anomalies on the graph. The height is

very big but the foot size is not. I can see this because the points

are far away from the line of best fit.

The graph shows a positive correlation, which means there is a

positive gradient. As the value of the y-axis increases, so does the

value of the x-axis, which means that in general, as the height

increases, so does the foot size. This means when I square root the

value of r2, to get r, I know to take the positive square root of

0.69. For the above graph, r=0.83 to 2sf. For graphs showing positive

correlation, the closer the value of r is to the line, the stronger

the correlation. A positive square root and a high value of r suggests

that the hypotheses I made above is correct. It then is possible to