HELP PLEASE! Find the 15th term of the sequence defined by the explicit rule

f(n)=4n-3

Which number produces a rationale number when multiplied by 1/5

{0,1,2,3,4,5,6,20,21,22,23,24,25} the distribution is considered to be: skewed the right, skewed the left, not skewed?

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.