HOMEWORK

Mp model with mathematics explain how the number of text messages dario sent and the cost form an arithmetic sequence.then write an expression to find dario's text messaging bill if he sends n text messages over 250.

In a class, there are 12 girls. if the ratio of boys to girls is 5: 4 how many boys are there in the class

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.