Download presentation

Presentation is loading. Please wait.

Published byAriana Stanley Modified over 3 years ago

1
CORRELATION To be able to plot scattergraphs accurately To be able to describe and interpret correlation To be able to calculate Sxx, Syy, Sxy and the product moment correlation coefficient (r) To understand the limitation of product moment correlation

2
Scattergraphs Vehicles (x) Millions 8.613.412.89.31.39.413.1 Accidents (y) thousands 33513048122346 4.913.59.67.59.823.32119.4 1836503435959969

3
Scattergraphs

4
Describe and interpret correlation 1st2nd 3rd4th Positive correlation – mainly in the 1 st and 3 rd quadrants Negative correlation – mainly in the 2 nd and 4 th quadrants No correlation – equally spread in all 4 quadrants

5
Describe and Interpret Correlation Describe Correlation State whether the correlation is strong or weak, positive, negative or no correlation Interpret Correlation Explain and analyse what the correlation actually means E.g. as an athlete trains for longer their active heartbeat reduces

6
Product Moment Correlation Coefficient Calculates the variation between bivariate data Variance = Σ(x – x)², Σ(y – y)², Σ(x – x)(y – y) n n n Sxx = Σ(x – x)² Syy = Σ(y – y)² Sxy = Σ(x – x)(y – y) Notice that variance = Sxx therefore variance x n = Sxx n

7
Product Moment Correlation Coefficient Notice that variance = Sxx therefore variance x n = Sxx n Sxx = variance x n Sxx = n Σx² - x ² n Sxx = Σx² - nx ² Sxx = Σx² - n Σx ² n Sxx = Σx² - n Σx ² n² Sxx = Σx² - Σx ² n Syy = Σy² - Σy ² n Sxy = Σxy - ΣxΣy n

8
Product Moment Correlation Coefficient r = Sxy Sxx Syy

Similar presentations

OK

Chapter 2 Bivariate Data Scatterplots. A scatterplot, which gives a visual display of the relationship between two variables. In analysing the.

Chapter 2 Bivariate Data Scatterplots. A scatterplot, which gives a visual display of the relationship between two variables. In analysing the.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on automobile related topics about information Ppt on boilers operations with fractions Ppt on layer 3 switching tutorial Free download ppt on triangles for class 9 Ppt on natural and artificial satellites names Ppt on case study of infosys Ppt on types of parallelograms worksheets Ppt on mammals and egg laying animals are called Ppt on quality control in industrial management Ppt on rural entrepreneurship