Solve this math question:
mary's car uses 8 gallons of gas to travel 340 miles. after a mechanic worked on the car, it used 7 gallons of gas to travel 350 miles. if gas costs approximately $4 per gallon, how much less, to the nearest cent per mile, did it cost to run the car after the mechanic worked on it?

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).