The Statistical Abstract of the United States (109th edition) reported that the average cost per day of owning an automobile in the United States is $7.62 with standard deviation of $1.77. This includes the cost of the car, general maintenance, gasoline, and insurance. A random sample of 54 students who own cars found the average cost per day to be $6.78. Is the college student's average daily expense less than the national average

Which one ? is the answer and how to find this answer

Martha has a deck of cards. she has lost some of the cards, and now the deck only contains nine spades, eleven diamonds, eight clubs, and twelve hearts. martha predicts that whenever she draws a card from the deck without looking, she will draw a club one-fifth of the time. which activity would best allow martha to test her prediction? a. randomly draw a card from the box and see if it is a club. b. randomly draw a card. then, continue to draw another card until all eight clubs are drawn. c. randomly draw and replace a card 120 times. then, observe how close to 30 times a club is drawn. d. randomly draw and replace a card 100 times. then, observe how close to 20 times a club is drawn.

Parabolas y=−2x^2 and y=2x^2+k intersect at points a and b that are in the third and the fourth quadrants respectively. find k if length of the segment ab is 5.