Reference no: EM133040487

An accountant for a large department store has the business objective of developing a model to analyze the relationship between the number of invoices (variable X) and the amount of time to process them (variable Y). Sample data about the number of invoices processed and completion time (in hours) are collected from the past 32 working days (Invoice.xlsx).

(a) Construct a scatter plot of X and Y using the number of invoices as the x-axis and the completion time as the y-axis.

(b) Compute the covariance between X and Y.

(c) Compute the correlation coefficient between X and Y.

(d) Is there a relationship between two variables X and Y? Explain.

Required Excel (Invoice.xlsx).

Invoices    Time

103    1.5
173   2.0
149   2.1
193   2.5
169   2.5
29    0.5
188   2.3
19    0.3
201   2.7
58   1.0
110   1.5
83   1.2
60   0.8
25    0.4
60    1.8
190   2.9
233   3.4
289   4.1
45    1.2
70    1.8
241   3.8
163   2.8
120   2.5
201   3.3
135   2.0
80   1.7
77   1.7 
222   3.1
181   2.8
30     1.0
61     1.9
120   2.6