It took a submarine 15 seconds to drop 75 feet below the surface of the water. If it descended at a constant rate, what was the change in the submarine’s elevation each second?
A.6 feet per second
b.-5 feet per second
c.1,350 feet per second
d.-1,350 feet per second

Atextile fiber manufacturer is investigating a new drapery yarn, which the company claims has a mean thread elongation of 12 kilograms with a standard deviation of 0.5 kilograms. the company wishes to test the hypothesis upper h subscript 0 baseline colon mu equals 12 against upper h subscript 1 baseline colon mu less-than 12 using a random sample of n equals 4 specimens. calculate the p-value if the observed statistic is x overbar equals 11.8. round your final answer to five decimal places (e. g. 98.76543).