Question

SOMEONE PLSSS HELP ME! An water well is to be drilled in the desert where the soil is either rock, clay or sand. The probability of rock P(R) = 0.53. The clay probability is P(C) = 0.21. The sand probability is P(S) = 0.26. It if it rock, a geological test gives a positive result with 35% accuracy. If it is clay, this test gives a positive result with 48% accuracy. The test gives a 75% accuracy for sand. Given the test is positive, what is the probability that soil is rock, P(sand | positive)?

Answer 1

ANY IDEAS?

Answer 2

hmm give me a sec to think

Answer 3

Thank you so much

Answer 4

I was thinking conditional probability???

Answer 5

what is the probability that soil is rock, P(sand | positive)? um do you mean probability that the soil is both rock and sand????

Answer 6

thats the part that is getting me

Answer 7

it clearly ask for the probability of soil being rock...... not to sure about the other part

Answer 8

really buggin me lol

Answer 9

well it b .53 since taht rock info is given... but that little extra part on sand idk what that means or is even saying tbh

Answer 10

:|

Answer 11

wait i think i figured it out

Answer 12

sweet

Answer 13

P(sand | positive) = 0.405








P(sand | positive) = 0.209








P(sand | positive) = 0.385








P(sand | positive) = 0.26

Answer 14

thats my options

Answer 15

nope srry i cannot figure this one out atm... i need time and i gtg for a bit but gl

Answer 16

thx anyways