Answer:
0.6892 = 68.92% of bottles are within specification.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
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.
On average, each bottle contains 2.07 liters of soda, with a standard deviation of 0.06 liters.
This means that [tex]\mu = 2.07, \sigma = 0.06[/tex]
The plant’s quality manager wants to determine how well the process is operating.
To do this, we find the proportion of bottles within specification.
The specification limits for a bottle of soda are 2.1 liters and 1.9 liters
This is the pvalue of Z when X = 2.1 subtracted by the pvalue of Z when X = 1.9. So
X = 2.1
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{2.1 - 2.07}{0.06}[/tex]
[tex]Z = 0.5[/tex]
[tex]Z = 0.5[/tex] has a pvalue of 0.6915.
X = 1.9
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{1.9 - 2.07}{0.06}[/tex]
[tex]Z = -2.83[/tex]
[tex]Z = -2.83[/tex] has a pvalue of 0.0023
0.6915 - 0.0023 = 0.6892
0.6892 = 68.92% of bottles are within specification.