Answered

The J.O. Supplies Company buys calculators from a Korean supplier. The probability of a defective calculator is 10%.If 10 calculators are selected at random, what is the probability that 3 or more of the calculators will be defective?
A. 0.0702
B. 0 .2639
C. 0.0016
D. 0

Answer :

Answer:

A. 0.0702

Step-by-step explanation:

The probability that 3 or more of the calculators will be defective is 1 minus the probability that exactly zero, one or two calculator are defective:

[tex]P(X \geq 3) = 1- (P(X=0)+P(X=1)+P(X=2))\\[/tex]

For X= 0:

[tex]P(X=0) = (1-0.10)^{10}=0.34868[/tex]

For X= 1:

[tex]P(X=1) = 10*0.1(1-0.10)^{9}=0.38742[/tex]

For X=2

[tex]P(X=2) = \frac{10!}{(10-2)!2!}*0.1^2(1-0.10)^{8}=0.19371[/tex]

Therefore:

[tex]P(X \geq 3) = 1- (0.34868+0.38732+0.19371)\\P(X \geq 3) =0.0702[/tex]

The probability that 3 or more of the calculators will be defective is 0.0702.

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