Machine Shop 4
Project - Fundamentals of SPC
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Part # 4A
Part Desc: Fundamentals of SPC
Quantity Req.: 80%
Required (4 pts per answer)
1. Consider the following data . Blueprint
Specification = 2.250
Code the data (hint: 2.251 should equal 1
the sample standard deviation.
2. Below you will
find a standard bell curve. Statisticians have found that 99.7% of all parts
will be within +/- 3 standard deviations. Label the percentage amounts of any
parts that will fall under each deviation. (This does not apply to any
particular parts) Fill in the generic percentages.
3. Holes are
measured after a drill press operation. The mean was found to be 1 (coded data)
and the standard deviation was found to be 3 (coded data).
the parts of the bell curve with the actual standard deviations (coded)
and the percentages.
1,000 parts are run, how many will be between -5 and -2 ?
many parts will be between –2 and +4 ?
our tolerance was –2 to + 7, how many scrap parts would we have?
4. Consider the
following data. -3, 2, -1, -2, -4, -1,
-2, 0,-2, 3, 0, -1, -1, 4, 2, 2, 0, 0, 1, 4
Calculate the mean
Calculate the sample standard deviation.
Construct a histogram by shading in the boxes and labeling the
Does it look like normal distribution? (circle one ) Yes or No