the manager of a grocery store has taken a random sample of 100 customers. the average length it took these 100 customers to check out was 3.0 minutes. It is known that the sd of the check out time for all customers who shop at this grocery store is one minute. The standard error of the sample mean equals

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.

To prove that angle def = angle dgf by sas, what additional information is needed? def congruent to dgf dfe congruent to dfg de congruent to dg dg congruent to gf

Abag contains pieces of paper numbered from 5 to 9. a piece of paper is drawn at random. what is the theoretical probability of drawing a number less than 8?