Question

The two companies produced the production of a plastic part used in automobile production.
Operate. This plastic piece is subject to wear during use. Therefore, it is desired to compare the amount of wear of plastic parts produced by the two companies. Friction wear was applied by taking samples of 25 units randomly from both companies and after 1000 cycles wear amounts were observed. Average wear rate of 20 mg / 1000 cycles for the first company and standard deviation of wear 1.5 mg / 1000 cycles, wear for the second company
the average was 12 mg / 1000 cycles and the wear standard deviation was 1.8 mg / 1000 cycles. It is assumed that the wear amount of both masses shows normal distribution with the same variance.
a) For the difference between the average of wear amount of plastic parts produced by the two companies, establish my confidence interval of 98%. Interpret the result. Can it be said that the amount of wear of the plastic material produced by the first company is higher?
b) For the average amount of wear of the plastic part produced by the second company, establish a 95% confidence interval. Interpret the result.

Answer 1

Question is answered below.