Knobs Lab Report

A company has specified that the acceptable size of a knob that is to be produced is (0.140 ± 0.003) inches. In this lab, the dimensions of the knobs produced in one day are tested for discrepancy in order to pass control testing. This lab also reports the probability that knobs with the acceptable dimension will be produced.
MATERIALS AND METHODS
Using Microsoft Excel, a histogram was created displaying the three documented dimensions of 15 batches of knobs. This histogram was obtained in order to provide a clear visible representation of which value occurred most frequently. After this, the sample mean, standard error , sample standard deviation, and the sample variance were calculated both manually and by the Microsoft Excel software. The 95% and 99% confidence range was then calculated. Lastly using the sample mean and sample standard deviation calculated earlier, a list of random numbers was generated through Excel and a histogram was created using the data.
RESULTS AND DISCUSSION
Manually calculated using the proper formulas, the standard error varied by .0001; 0.5702, and the population with 90% confidence was greater by 0.0006; 0.9588. If on another day the dimension of one knob was recorded to be 0.114 inches, it would be an outlier due to the fact that it is out of the range of all the other knobs which is 0.133 to 0.149 inches. This number is far from the mean and if the 99% confidence level of the sample were determined this knob is in an area in which it could not be counted. Therefore, this knob would not be an acceptable