Use Bayes' Rule to Find the Indicated Probability

question 44

Multiple Choice

Use Bayes' rule to find the indicated probability.
-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) ?

• A)P(sand | positive)= 0.405
• B)P(sand | positive)= 0.385
• C)P(sand | positive)= 0.26
• D)P(sand | positive)= 0.209

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Definitions:

Soma

The cell body of a neuron, containing the nucleus and cytoplasm.

Dendrite

Branched extensions of a neuron that act to conduct the electrochemical stimulation received from other neural cells to the cell body, or soma.

Dendrites

Branch-like extensions of neurons that receive signals from other neurons or sensory inputs.

Neurotransmitters

Chemical messengers that transmit signals across a chemical synapse, from one neuron (nerve cell) to another target neuron, muscle cell, or gland cell.