An engineer has designed a value that will regulate water pressure on an automobile engine. The valve was tested on 160 engines and the mean pressure was 4 lbs/square inch. Assume the standard deviation is known to be 0.9 if the value was designed to produce a mean pressure of 4.2 lbs is there a sufficient evidence at the 0.2 level that the valve performs below specifications? State the bulk and alternative hypotheses for the above scenario

Ahome improvement store rents it’s delivery truck for $19 for the first 75 minutes and $4.75 for each additional 1/4 hour. if a customer rented the truck at 11: 10 am and returned the truck at 1: 40 pm the same day, what would his rental cost be?

1- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis.2- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in the first question?

Erik buys 2.5 pounds of cashews. if each pound of cashews costs $7.70, how much will he pay for the cashews?