Question

Consider the following scenario. A marble factory produces marbles that weigh 10 grams apiece. The standard deviation of the weight of a bag of 100 marbles is 20 grams. You buy a bag of 100 marbles that weighs 960 grams. Use mathematical calculations to prove 95% confidence that the purchased bag of marbles did not come from the factory.

Answer 1

Answer: 100*10= 1000grams - Standard deviation is 20 which gives you a plus or minus of 20 grams. Meaning the factory bag would weigh between 980 grams to 1020 grams.

Answer 2

Marble Factory: 10 Grams A piece

Standard: 100 = 20gs (you got one thats 960 Grams.)

Basically it's fake because they only way 10 grams a piece at that factory and in this case the marbles weigh more