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5.28 A manufacturer knows that on average 20% of the electric toasters produced require repairs within 1 year after they are sold. When 20 toasters are randomly selected, find appropriate numbers x and y such that (a) the probability that at least x of them will require repairs is less than 0.5; (b) the probability that at least y of thE?

Respuesta :

Answer:

A) probability that at least x of them will require repairs is less than 0.5 is 4

Step-by-step explanation:

sample size, n = 20

p = success probability of toaster = 0.2

q = failure probability of toaster =1- p = 1- 0.2 =0.8

mean, , μ = n * p = 20 * 0.2 = 4

standard deviation, [tex]\sigma = \sqrt{npq} = \sqrt{(20 * 0.2 *0.8)} = 1.79[/tex]

a) the probability that at least some of them require repairs < 0.5.

for [tex]p \geq 0.5[/tex] value of z = 0

we know [tex]z  =\frac{x -\mu}{\sigma}[/tex]

[tex]0 = \frac{X -4}{1.79}[/tex] from z table

X =  4

B)  SECOND PART IS INCOMPLETE { DATA IS INCOMPLETE}

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