In: Finance
A quality characteristic of interest for a flour-bag-filling process is the weight of the flour in the individual bags. If the bags are under filled, the company may be in violation of the truth-in-labeling laws. In this example, the label weight on the package indicates that, on average, there are 10 pounds of flour in a bag. If the average amount of flour in a bag exceeds the label weight, the company is giving away product. Getting an exact amount of flour in a bag is problematic because of variation in the temperature and humidity inside the factory, and the extremely fast filling operation of the machine (approximately 150 bags a minute). The following table provides the weight in pounds of a sample of 70 bags produced in one hour by a single machine: | ||||||||||
10.31 | 9.74 | 10.01 | 10.04 | 10.10 | 10.45 | 10.37 | 10.19 | 10.10 | 9.74 | |
10.37 | 9.85 | 10.38 | 10.11 | 10.11 | 9.92 | 9.72 | 9.78 | 9.97 | 10.50 | |
9.84 | 10.22 | 9.70 | 9.75 | 10.02 | 10.19 | 10.07 | 10.36 | 10.39 | 9.83 | |
10.14 | 10.42 | 10.11 | 9.73 | 10.31 | 10.40 | 9.86 | 10.45 | 10.45 | 10.25 | |
10.28 | 9.82 | 9.74 | 10.23 | 10.41 | 10.20 | 9.81 | 10.06 | 10.32 | 10.43 | |
10.24 | 9.73 | 10.06 | 10.31 | 10.10 | 10.34 | 9.78 | 9.88 | 10.05 | 9.96 | |
9.85 | 10.27 | 10.32 | 10.35 | 10.06 | 10.07 | 9.86 | 10.37 | 10.47 | 10.37 | |
a) Compute the mean by using the function, =AVERAGE() | ||||||||||
Compute the median using =MEDIAN() | ||||||||||
Median | ||||||||||
b) Compute the first and third quartiles, by using either =QUARTILE.INC() or =QUARTILE.EXC() for both the First and Third Quartiles | ||||||||||
First Quartile | ||||||||||
Third Quartile | ||||||||||
c) Compute the range, interquartile range, variance, standard deviation, and coefficient of variation. | ||||||||||
Range | Use the functions, =MAX()-MIN() | |||||||||
Interquartile range | ||||||||||
Variance | Use the function =VAR.S() | |||||||||
Standard deviation | Use the function =STDEV.S() | |||||||||
Coefficient of variation.
Coefficient of variation is the standard deviation divided by the
mean. Note that coefficient of variation should be expressed in percentage |
The question is solved using Excel as per the requirement. The excel sheet is attached as well.
a) Mean = 10.11
Median = 10.11
b) First Quartile = 9.86
Third Quartile = 10.34
c) Range = 0.80
Interquartile Range = 0.48
Variance = 0.06
Standard Deviation = 0.24
Coefficient of Variance = 2.40%