# Question: A large sample of lenses was randomly selected and evaluated

A large sample of lenses was randomly selected and evaluated for a particular lens dimension. It was then compared to its specification range of nominal (0.000) ± 0.030 units. One hundred ten lenses were evaluated. Data were coded in two ways and are shown below:

Source: Courtesy of Bausch & Lomb [Variable not named & data coded at B&L's request]

a. Calculate the mean and standard deviation of the data.

b. Create a histogram, and comment on the pattern of variability of the data.

c. Use tests for normality and/or the empirical rule as confirmation of the normal appearance. Explain your findings.

d. Determine the observed percentage of conformance to specification. That is, what percentage of the measurements fall within the specification range of 0.000 + - 0.030 units?

Source: Courtesy of Bausch & Lomb [Variable not named & data coded at B&L's request]

a. Calculate the mean and standard deviation of the data.

b. Create a histogram, and comment on the pattern of variability of the data.

c. Use tests for normality and/or the empirical rule as confirmation of the normal appearance. Explain your findings.

d. Determine the observed percentage of conformance to specification. That is, what percentage of the measurements fall within the specification range of 0.000 + - 0.030 units?

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