if the cost price of 10 articles is equal to the cost price if 12 articles find the gain of loss percent

Acar dealership pays you 5% commission on your first $10,000 on car sales and 8% commission on the sale amount over $10,000 if you sold a $12,000 car how much is your commission

Asimple random sample of size nequals14 is drawn from a population that is normally distributed. the sample mean is found to be x overbar equals 70 and the sample standard deviation is found to be sequals13. construct a 90% confidence interval about the population mean

A. 127 cm^2 b. 144.5 cm^2 c. 172 cm^2 d. 50 cm^2