Scores on a certain test are normally distributed with a variance of70. A researcher wishes to estimate the meanscore achieved by all adults on the test. Find the sample size needed to assure with 95 percent confidence thatthe sample mean will not differ from the population mean by more than2 units.

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.

Which shows a reasonable estimation for 124% of 42 using the distributive property?

30 ! the graph shows the number of siblings different students have. select from the drop-down menus to correctly complete the statement.