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 6 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 6 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

To find X bar for 7 am, we need to use the average of the samples taken at 6 am, 3 am, and 12 am.

6 am: 6.74
3 am: 6.80
12 am: 6.76

Taking the average of these values gives us:

(X bar) = (6.74 + 6.80 + 6.76)/3 = 6.76

Therefore, the closest answer choice to this value is B: 6.74.

A New Machine Is Set or Calibrated to Fill Tubes