you buy 20 of your favorite songs from the web site that charges $0.97 for each song. what is the cost of 20 songs? use mental math

Which is the graph of f(x) = (4)x? image for option 1 image for option 2 image for option 3 image for option 4

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.

Write the equations in logarithmic form 9^4=6,561