2 Suppose we found the age and weight of a sample of 10 adults. Create a scatterplot of the data below.Is there any relationship between the age and weight of these adults?Age24304128504649352039Wt256124320185158129103196110130
3 Create a scatterplot of the data below. Suppose we found the height and weight of a sample of 10 adults.Create a scatterplot of the data below.Is there any relationship between the height and weight of these adults?Is it positive or negative? Weak or strong?Ht74657772686062736164Wt256124320185158129103196110130
4 The farther away from a straight line – the weaker the relationship The closer the points in a scatterplot are to a straight line - the stronger the relationship.The farther away from a straight line – the weaker the relationship
5 Identify as having a positive association, a negative association, or no association. +1. Heights of mothers & heights of their adult daughters-Age of a car in years and its current value+Weight of a person and calories consumedHeight of a person and the person’s birth monthNONumber of hours spent in safety training and the number of accidents that occur-
6 Correlation Coefficient (r)- A quantitative assessment of the strength & direction of the linear relationship between bivariate, quantitative data Pearson’s sample correlation is used most parameter - r (rho) statistic - r
7 Calculate r. Interpret r in context. Speed Limit (mph)555045403020Avg. # of accidents (weekly)28252117116Calculate r. Interpret r in context.There is a strong, positive, linear relationship between speed limit and average number of accidents per week.
8 Properties of r (correlation coefficient) legitimate values of r is [-1,1]Strong correlationNoCorrelationModerate CorrelationWeak correlation
9 The correlations are the same. value of r does not depend on the unit of measurement for either variablex (in mm)yFind r.Change to cm & find r.The correlations are the same.
10 value of r does not depend on which of the two variables is labeled x ySwitch x & y & find r.The correlations are the same.
11 value of r is non-resistant xyFind r.Outliers affect the correlation coefficient
12 r = 0, but has a definite relationship! value of r is a measure of the extent to which x & y are linearly relatedA value of r close to zero does not rule out any strong relationship between x and y.r = 0, but has a definite relationship!
13 Minister data:r = .9999So does an increase in ministers cause an increase in consumption of rum?