Part C
Find the average and margin of error for each of the following: the entire sample, 1950s records, 1960s records, 1970s records, Company A records, Company B records, and Company C records.
Part D
An oil embargo in the 1970s made vinyl more expensive, which some collectors say caused a decrease in average vinyl weight from 1970 onward. Do the data support this claim? Why or why not? Be sure to discuss averages, margins of error, and anything else that is relevant in your answer.
