Machine Shop 4

Please turn into instructor after completing required operations

Part # 4A

Part Desc: Fundamentals of SPC

##### Quantity Req.: 80% Required (4 pts per answer)

1.  Consider the following data . Blueprint Specification = 2.250

1.

Code the data (hint: 2.251 should equal 1 coded)

1. Find the mean.

1. Find 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.

 2%

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).

1. Label the parts of the bell curve with the actual standard deviations (coded) and the percentages.

 1

1. If 1,000 parts are run, how many will be between  -5 and -2 ?

1. How many parts will be between –2 and +4 ?

1. If 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

a.        Calculate the mean

b.       Calculate the sample standard deviation.

c.        Construct a histogram by shading in the boxes and labeling the chart.

d.       Does it look like normal distribution? (circle one )         Yes        or       No