Airplanes are sometimes used to fight fires . A certain airplane can deliver 3.9 * 10^4 liters of water in one trip . How much water can this airplane reliever in 7 trips ? write the answer in scientific notation .

How do i make someone brainliest? (if you answer me, i might be able to make you brainliest! )

Jada has a meal in a restaurant she adds up the prices listed on the menu for everything they ordered and gets a subtotal of $42.00. after tax the total is 45.99. what percentage of the subtotal is the total?

Afactory makes propeller drive shafts for ships. a quality assurance engineer at the factory needs to estimate the true mean length of the shafts. she randomly selects four drive shafts made at the factory, measures their lengths, and finds their sample mean to be 1000 mm. the lengths are known to follow a normal distribution whose standard deviation is 2 mm. calculate a 95% confidence interval for the true mean length of the shafts. input your answers for the margin of error, lower bound, and upper bound.