Asample in which everyone in a population has an equal or known chance of being selected is called

Two technicians are discussing how to test a car's exhaust by holding a small piece of paper within an inch of the tailpipe mouth. technician a says that if the paper is vibrating due to a "puffing" output from the tailpipe, this signals a smoothly running engine. technician b says that if the paper is being drawn toward the tailpipe, this could indicate burned exhaust valves. who is correct? a. technician b b. both technicians a and b c. technician a d. neither technicians a or b

Anna’s mother prepares sauerkraut, a fermented dish made from finely cut cabbage and salt. lactobacillus bacteria present on the surface of the cabbage combine with salt to turn the cabbage into a crunchy, sour dish. what chemical process occurs to create this dish? a. alcoholic fermentation b. cellular respiration c. conservation d. lactic acid fermentation e. photosynthesis

When do you think it’s best to take the psat (what grade year / when in the year)?