A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then,once the machine is running,a sample of six tubes is taken every three hours and weighed with the following results: What is X-bar for 7 am?
A)6.72
B)6.74
C)6.78
D)6.80

Question

A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then,once the machine is running,a sample of six tubes is taken every three hours and weighed with the following results:  What is X-bar for 7 am?
A)6.72 
B)6.74 
C)6.78 
D)6.80

Quizplus · Accepted Answer

X-bar for 7am can be calculated by finding the arithmetic mean of the six sample weights taken at 7am. The given data does not specify which tube corresponds to 7am, so we cannot directly calculate X-bar. However, we can assume that the samples taken every three hours are representative of the entire run, and therefore, the overall mean weight of the tubes should be close to 6.75 ounces. Based on the sample data, the X-bar for the entire run is likely to be somewhere between 6.72 and 6.80 ounces, with a higher probability of being closer to 6.74 ounces, which is the midpoint of the range. Therefore, the best choice is B, 6.74.

A New Machine Is Set or Calibrated to Fill Tubes