The piston diameter of a certain hand pump is 0.6 inch. the manager determines that the diameters are normally distributed, with a mean of 0.6 inch and a standard deviation of 0.003 inch. after recalibrating the production machine, the manager randomly selects 26 pistons and determines that the standard deviation is 0.0026 inch. is there significant evidence for the manager to conclude that the standard deviation has decreased at the alpha equals 0.10 level of significance?

Tom had a total of $220 and he spent $35 on a basketball ticket . what percent of his money did he have left?

Find the constant of variation for the relation and use it to write an equation for the statement. then solve the equation.

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.