Question 4 of 20, Step 1 of 1 Correct An engineer has designed a valve that will regulate water pressure on an automobile engine. The valve was tested on 280 engines and the mean pressure was 6.2 Ibs/square inch. Assume the standard deviation is known to be 0.8. If the valve was designed to produce a mean pressure of 6.1 lbs/square inch, is there sufficient evidence at the 0.05 level that the valve performs above the specifications? State the null and alternative hypotheses for the above scenario. Answer Tables ...... Keypad Keyboard Shortcuts Ho: Ha