How many strings of seven hexadecimal digits do not have any repeated digits? (b) How many strings of seven hexadecimal digits have at least one repeated digit? (c) What is the probability that a randomly chosen string of seven hexadecimal digits has at least one repeated digit? (Round your answer to the nearest tenth of a percent.) %

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.

Which expression is rational? 6. , square root two, square root 14, square root 49

15 points what is the end behavior of this graph? & what is the asymptote of this graph?