Assignment 6 - Ryan Kindall

Assignment #6 Chapter 2 Scatterplots pp. 85-100 Homework: #1 + 2.24, 2.25, 2.27, 2.34 Scatterplot : pairs of values plotted on a bi-coordinate plane Explanatory variable typically on the x axis ; Response variable typically on the y axis In scatterplot consider Form: linear or curvilinear Direction Positive association (dots tend upward as you more from left to right) Negative association (dots tend downward as you more from left to right) Zero association (the dots appear to be random) Strength of relationship Dots clustered more closely represents a stronger relationship Dots scattered more widely represent a weaker relationship Outliers (extreme values) 1. Identify the form of the following graphs using the words “ linear ”, “ curvilinear ”, or “ random ” Also identify the strength of the relationship using the words “ strong ”, “ moderate ”, or “ weak ” Form: Form: Form: Strength: Strength: Strength: 2.34 (p 99): The World Bank collects data on internet use (number of users per 100 people) and birth rate (number of births per 1000 people). Figure 2.13 (p. 99 bottom of page) shows the scatter plot for 106 countries (a) Describe the relationship between variables (b) Your friend looks at the plot and concludes that using the Internet will decrease the number of babies born. Your friend is, of course, crazy. Explain what is the real relationship between these two variables. 2.24 (p 97): Plot data for normal young men comparing strength of dominant and non-dominant arms. linear curvilinear negative relationship strong moderate Weak Negative relationship (probably curvilinear) . High birthrate is associated with low internet usage ; low birthrate is associated with high internet usage less developed countries have higher birthrate and lower internet usage : more developed countries have lower birthrate and higher internet usage