A tennis ball follows a path described by the function h(d) = 1/171 (d- 9)2 +0.00, where h is the height of the ball above the court and d is the horizontal distance of the ball from the tennis player, both in metres. From what height
above court level rounded to the nearest 0.1 meter did the tennis player hit the ball?

For what value of x does 4x = (1/8) x + 5?

Nine more than four times a number is the same as one less than twice the number. find the number?

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.