The valve was tested on 210 engines and the mean pressure was 5.0 pounds/square inch (psi). Assume the population standard deviation is 0.9. The engineer designed the valve such that it would produce a mean pressure of 4.9 psi. It is believed that the valve does not perform to the specifications. A level of significance of 0.02 will be used. Find the value of the test statistic. Round your answer to two decimal places.

1.6101529

Step-by-step explanation:

Given the following :

Number of samples (n) = 210

Sample mean (x) = 5

Population standard deviation = 0.9

Population mean (m) = 4.9

Since the standard deviation of the population is known, we can use the z statistic

Z = (x - m) / standard error

Standard error = sd / √n

Standard error = 0.9 / √210

Standard error = 0.9 / 14.491376

Standard error= 0.0621059

Z statistic = (5 - 4.9) / 0.0621059

Z statistic = 0.1 / 0.0621059

Z statistic = 1.6101529

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.

hi! i think the answer is 1/2 : )