When testing for differences of means, the t-statistic t equals StartFraction Upper Y overbar Subscript m Baseline minus Upper Y overbar Subscript w Over SE left parenthesis Upper Y overbar Subscript m Baseline minus Upper Y overbar Subscript w right parenthesis EndFraction

, where SE left parenthesis Upper Y overbar Subscript m Baseline minus Upper Y overbar Subscript w Baseline right parenthesis equals StartRoot StartFraction s Subscript m Superscript 2 Over n Subscript m EndFraction plus StartFraction s Subscript w Superscript 2 Over n Subscript w EndFraction EndRoot

has:

A. a student t distribution if the population distribution of Y is not normal.

B. cannot be computed unless n Subscript m equals n Subscript w.

C. a normal distribution even in small samples.

D. a student t distribution if the population distribution of Y is normal.

Yolo windows, a manufacturer of windows for commercial buildings, reports the following account information for last year (all costs are in thousands of dollars): information on january 1 (beginning): direct materials inventory $ 89 work-in-process inventory 111 finished goods inventory 1,620 information for the year: administrative costs $ 3,610 direct labor 12,900 direct materials purchases 8,210 factory and machine depreciation 11,720 factory supervision 774 factory utilities 940 indirect factory labor 2,880 indirect materials and supplies 688 marketing costs 1,480 property taxes on factory 282 sales revenue 45,800 information on december 31 (ending): direct materials inventory $ 94 work-in-process inventory 138 finished goods inventory 1,430 required: prepare an income statement with a supporting cost of goods sold statement. (enter your answers in thousands of dollars (i.e., 234,000 should be entered as