4.1 scatterplots

Question 1

scatterplot

Answer 1

each individual in the data set makes an ordered pair of numbers, and each ordered pair is plotted on a set of axes

Question 2

making a scatterplot on ti-84

Answer 2

1) put x-values in L1 and y-values in L2. 2) press 2nd, Y= then 1 to access plot 1 menu. Press On and pick the scatterplot option. 3) press zoom, 9 to see the plot.

Question 3

types of association

Answer 3

positive, negative, linear, weak and strong, no linear association

Question 4

correlation coefficient

Answer 4

a number that measures the strength of the linear relationship between two variables

Question 5

correlation coefficient properties

Answer 5

1)
always between -1 and 1. aka -1 (less than or equal) r (less than or equal) 1.
2) sensitive to outliers and can be misleading when outliers are present
3) doesnt matter which variable is x and y
4)only measures the strength of the linear relationship
5) doesnt depend on the units of the variables

Question 6

correlation is not causation

Answer 6

shoe size and vocabulary are correlated but doesnt that changing one variable will cause the other to change

Question 7

a correlation coefficient is not appropriate

Answer 7

when there are outliers

Question 8

a correlation coefficient is appropriate

Answer 8

when their relationship is linear

Question 9

positive or negative association?

Answer 9

karats (weight) in a diamond vs its cost is positive

Question 10

positive or negative association?

Answer 10

weight of a car in lbs and its fuel efficiency in mpg(miles per gallon) is negative