成管會一題請教 - 會計

Come-Clean Corporation produces a variety of cleaning compounds and household
use. While most of its products are processed independently, a few are related, such as the company’
s Grit337 and its Sparkle silver polish.

Grit337 is a coarse cleaning powder with many industrial uses. It costs＄1.6
a pound to make, and it has a selling price of＄2.00 a pound .
A small portion of the annual production of Grit337
is retained in the factory for further processing.
It is combined with several others ingredients to from a paste
that is marketed as Sparkle silver polish.
The silver polish sell for ＄4.00 per jar.
This further processing requires one-fourth pound of Grit 337 per jar of
silver polish. The additional direct costs involved in the processing
of a jar of silver polish are：

Other ingredients ＄0.65
Direct labor 1.48
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Total direct cost ＄2.13

Overhead costs associated with the processing of the silver polish are：
Variable manufacturing overhead cost 25％ of direct labor cost
Fixed manufacturing overhead cost(per month)：
Production supervisor ＄3,000
Depreciation of mixing equipment ＄1,400
The production supervisor has no duties other than to oversee production
of the silver polish. The mixing equipment is special-purpose equipment
acquired specifically to produce the silver polish. Its resale value
is negligible and it does not wear out through use.
Direct labor is a variable cost at Come-Clean Corporation. Advertising costs
for the silver polish total ＄4,000 per month.
Variable selling costs associated with the silver polish are 7.5％ of sales.
Due to a recent decline in the demand for silver polish, the company is
wondering whether its continued production is advisable.
The sales manager feels that it would be more profitable to sell all of
the Grit 337 as a cleaning powder.

Required：
What is the minimum number of jars of silver polish that must be sold each
month to justify the continued processing of Grit 337 into silver polish？
Explain . Show all computations in good from.
解答
單位變動成本=$0.65+$1.48×1.25+$4×7.5%=$2.8
設必須出售銀器亮光劑的最少瓶數為X 瓶
$4*X -$2*1/4X＝$2.8*X+$3,000+$4,000
X＝10,000
結論：必須出售銀器亮光劑的最少10,000 瓶數才值得加工。
我的問題是為什麼Depreciation of mixing equipment ＄1,400
不用算呢???

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