Question

A beverage distributor has a facility that bottles beer. Beer bottles are supposed to be filled to 12 oz but there are slight variations. As part of quality control, they randomly sample bottles of beer and measure how many ounces they contain. In the most recent sample, the found an average fill of 12.01 oz with a standard deviation of 0.89. Quantitative Question 2a If one of the bottles of sampled beer was filled to 10.98 oz, what is its associated zscore

Answer 1

Its associated z-score is -1.16.

Explanation:

Z-score:

In a set with mean
`\mu` and standard deviation
`\sigma`, the zscore of a measure X is given by:

`Z = (X - \mu)/(\sigma)`

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In the most recent sample, the found an average fill of 12.01 oz with a standard deviation of 0.89.

This means that
`\mu = 12.01, \sigma = 0.89`.

If one of the bottles of sampled beer was filled to 10.98 oz, what is its associated zscore

This is Z when X = 10.98. So

`Z = (X - \mu)/(\sigma)`

`Z = (10.98 - 12.01)/(0.89)`

`Z = -1.16`

Its associated z-score is -1.16.