Question

3.An accountant for a large department store would like to develop a model to predict the amount of time it takes to process invoices. Data are collected from the 30 working days and the number of invoices processed and completion time (in hours) are used to obtain the following PHStat output. 1. The value of the t-test statistic to test whether time is linearly dependent on the number of invoices to be processed is? 2. The value of the coefficient of determinations is? 3. TThe accountant is expected to work an additional 0.013 hours (less than a minute) to process an additional invoice. True or false? 4 The value of the standard error of the estimated regression model is?

SUMMARY OUTPUT
Regression Statistics
Multiple R	0.945
R Square	0.892
Adjusted R Square	0.889
Standard Error	0.334
Observations	30
ANOVA
	df	SS	MS	F	Significance F
Regression	1	25.944	25.944	232.220	4.3946E-15
Residual	28	3.128	0.112
Total	29	29.072
	Coefficients	Standard Error	t Stat	P-value
Intercept	0.402	0.124	3.256	0.003
Invoices Processed	0.013	0.001	15.239	0.000

Answer 1

Solution :-

1)

From the given output,

The t - value correspoding to the Invoice Processed row = 15.239

Hence,

t-test statistic to test whether time is linearly dependent on the number of invoices to be processed

= 15.239

2)

Value of coefficient of determination

= R - square value given in the output

= 0.892

3)

The statement that the accountant is expected to work an additional 0.013 hours (less than a minute) to process an additional invoice is True.

This is because the coefficient of Invoices processed is0.013 which means that in order to process an additional invoice, the accountant would have to work an additional 0.013 hours.

4)

The value of standard error of estimated regression model is 0.334