TABLE 12-14
A filling machine at a local soft drinks company is calibrated to fill the cans at an average amount of 12 fluid ounces and a standard deviation of 0.5 ounces. The company wants to test whether the standard deviation of the amount filled by the machine is indeed 0.5 ounces. A random sample of 15 cans filled by the machine reveals a standard deviation of 0.67 ounces.
-Referring to Table 12-14, there is sufficient evidence to conclude that the standard deviation of the amount filled by the machine is not exactly 0.5 ounces when using a 10% level of significance.

Question

TABLE 12-14 
A filling machine at a local soft drinks company is calibrated to fill the cans at an average amount of 12 fluid ounces and a standard deviation of 0.5 ounces. The company wants to test whether the standard deviation of the amount filled by the machine is indeed 0.5 ounces. A random sample of 15 cans filled by the machine reveals a standard deviation of 0.67 ounces.
-Referring to Table 12-14, there is sufficient evidence to conclude that the standard deviation of the amount filled by the machine is not exactly 0.5 ounces when using a 10% level of significance.

Quizplus · Accepted Answer

The sample standard deviation of 0.67 ounces is significantly different from the hypothesized standard deviation of 0.5 ounces, and with a small sample size of 15, a chi-square test can be used to determine if this difference is statistically significant at the 10% level.

TABLE 12-14 A Filling Machine at a Local Soft Drinks Company Is