At a water bottling facility, a technician is testing a bottle filling machine that is supposed to deliver 750 milliliters of water. The technician dispenses 43 samples of water and determines the volume of each sample. The 43 samples have a mean volume of $\bar { x } = 751.1 \mathrm {~mL}$. The machine is out of calibration if the mean volume differs from $750 \mathrm {~mL}$.
The technician wants to perform a hypothesis test to determine whether the machine is ou calibration. The standard deviation of the dispensed volume is known to be $\sigma = 6.0$ value of the test statistic.
A) 1.20
B) 0.17
C) 2.94
D) 0.18

Question

Quizplus · Accepted Answer

The test statistic is calculated as:$$z = \frac{\bar{x} - \mu}{\sigma/\sqrt{n}} = \frac{751.1 - 750}{6.0/\sqrt{43}} = 1.20$$Therefore, the correct choice is A.

At a Water Bottling Facility, a Technician Is Testing a Bottle