Please help with this math problem :)

You paid $7.70 to the mail package that weighed 5.5 lb. right and solve any quetion to find the cost per pound ? ?

Which of these is and example of a literal equation? a) 6+30=6^2 b)3x-4y c)12=9+3x d)ax-by=k

Select the margin of error that corresponds to the sample mean that corresponds to each population: a population mean of 25, a standard deviation of 2.5, and margin of error of 5%