The following summary data on bending strength (lb-in/in) of joints is taken from the article "Bending Strength of Corner Joints Constructed with Injection Molded Splines" (Forest Products J., April, 1997: 89-92).

a. Calculate a 95% lower confidence bound for true average strength of joints with a side coating.
b. Calculate a 95% lower prediction bound for the strength of a single joint with a side coating.
c. Calculate an interval that, with 95% confidence, includes the strength values for at least 95% of the population of all joints with side coatings.
d. Calculate a 95% confidence interval for the difference between true average strengths for the two types of joints.

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Sample Sample Sample Type Size Mea SD Without side coating With side coating 10 10 095 9.59 63.23 5.96