Question

For each X-Y data set (n = 12):

  

Data Set (a)
X	64.7	25.9	65.6	49.6	50.3	26.7	39.5	56.0	90.8	35.9	39.9	64.1
Y	5.8	18.1	10.6	11.9	11.4	14.6	15.7	4.4	2.2	15.4	14.7	9.9

  

Data Set (b)
X	55.1	59.8	72.3	86.4	31.1	41.8	40.7	36.8	42.7	28.9	24.8	16.2
Y	15.7	17.5	15.2	20.6	7.3	8.2	9.8	8.2	13.7	11.2	7.5	4.5

  

Data Set (c)
X	53.3	18.1	49.8	43.8	68.3	30.4	18.6	45.8	34.0	56.7	60.3	29.3
Y	10.2	6.9	14.8	13.4	16.8	9.5	16.3	16.4	1.5	11.4	10.9	19.7

  

Click here for the Excel Data File

  

(a)

Match the data sets to the scatter plots below.

Data Set (a)

Data Set (b)

Data Set (c)

Data Set (a)

Data Set (b)

Data Set (c)

Data Set (a)

Data Set (b)

Data Set (c)

  

(b)	Use Excel to calculate the sample correlation coefficient for each data set. (Negative amounts should be indicated by a minus sign. Round your answers to 4 decimal places.)

  

Data Set (a)
Data Set (b)
Data Set (c)

  

(c)

Match the data sets to the scatter plot descriptions.

There appears to be a weak, positive relationship.

	Data Set (a)
	Data Set (b)
	Data Set (c)

There appears to be a strong, positive linear relationship.

	Data Set (a)
	Data Set (b)
	Data Set (c)

There appears to be a strong, negative linear relationship.

	Data Set (a)
	Data Set (b)
	Data Set (c)

Answer 1

Solution

a)

Scatter plot for Dataset (a)

Scatter plot for Dataset (b)

Scatter plot for Dataset (c)

b)

sample correlation coefficient

dataset a = -0.8841

dataset b = 0.90875

dataset c =0.170358

c)

(c)	Match the data sets to the scatter plot descriptions.

There appears to be a weak, positive relationship.

datset c

There appears to be a strong, positive linear relationship.

dataset b

There appears to be a strong, negative linear relationship

datset a