What is the probability of all cogs being defective

Prob (first defective) = 4 / 20 = 1/5

Prob(2nd defective) = 3/19

Prob (3rd defective) = 2/18 = 1/9

Pron 4th defective) = 1/ 17

Prob ( all 4 defective) = 1/5 * 3/19 * 1/9 * 1/17 = 1 / 4845 answer

x -

median = 1.25

range = 12-14.5

interquartile = q12-q14.5

y -

median = 1

range = 15-17

interquartile = q15-q17

the surface area is 124cm²

step-by-step explanation:

length: 4cm

width: 9cm

height:   2cm