Many fast-food restaurants have soft drink dispensers with preset amounts, so that when the operator merely pushes a button for the desired drink the cup is automatically filled. This method apparently saves time and seems to increase worker productivity. To test this conclusion, a business analyst randomly selects 18 workers from the fast-food industry, 9 from a restaurant with automatic soft drink dispensers and 9 from a comparable restaurant with manual soft drink dispensers. The samples are independent. During a comparable hour, the amount of sales rung up by the worker is recorded. Assume that [Math Processing Error]=.01 and that a t test is not appropriate. Test whether workers with automatic dispensers are significantly more productive (higher sales per hour).

Automatic Dispenser	Manual Dispenser
$153	$105
128	118
143	129
110	114
152	125
168	117
144	106
137	92
118	126