J.D. power and Associates calculates and publishes various statistics concerning car quality. The dependability score measures problems experienced during the past 12 months by original owners of three-year-old vehicles (those that were introduced for the 2017 model year). For these models of cars, Ford had 1.27 problems per car and Toyota had 1.12 problems per car. Let X be equal to the number of problems with a three-year-old Ford, and Y be equal to the number of problems with a three-year-old Toyota. If you purchased a Ford in the 2017 model year, what is the probability that in the past 12 months the car had a) Can X be distributed as a Poisson random variable? Justify your answer. b) zero problems? c) two or fewer problems? If you purchased a Toyota in the 2017 model year, what is the probability that in the past 12 months the car had d) zero problems? e) two or fewer problems? f) Compare your answers in (d) and (e) to those for the Ford in (b) and (c).

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Answer:

Follows are the solution to this question:

Step-by-step explanation:

The Ford car has an issue rate of 1.27.  

That means that [tex]\lambda = 1.27[/tex]

Here, [tex]X \sim poisson (\lambda = 1.27)[/tex]

In option (A) :

To make a random variable X a Poisson variable,  Parameter:

[tex]\to \lambda \leq 0 .[/tex]

The likelihood of success decreases with increased test numbers.  

Mathematics, as [tex]n \longrightarrow \infty, \ \ \ and \ \ \p \longrightarrow 0[/tex].

In option (B) :

You must find it: [tex]P(X =0)[/tex]

[tex]\to P(X=0) = \frac{e^{-\lambda}\cdot \lambda^{0} }{0!} \\\\\to \lambda= 1.27 \\\\=e^{-1.27} \\\\= 0.280832[/tex]

In Option (C):

You must find it: [tex]P( X \leq 2) \\[/tex]

[tex]\to P( X \leq 2) = P(X=0) +P(X=1)+P(X=2) \\\\= \sum_{x= 0}^{2} P(X=x) \\\\= \sum_{x= 0}^{2} \frac{e^{- \lambda} \lambda^{x} }{x!} \\\\= e^{-1.27}\sum_{x= 0}^{2} \frac{ 1.27^{x} }{x!} \\\\ = 0.863964[/tex]

In Option (d):

Its first rating is essential because failures in production could be detected  but before the total product becomes defective, this can be reduced.

In Option (e) :

The Toyata car has an issue rate of 1.12  

That means that [tex]\lambda = 1.12[/tex]  

Here, [tex]Y \sim poisson ( \lambda= 1.12)[/tex]

In Option (f):

You must find it: [tex]P(Y=0)[/tex]

[tex]\to P(Y=0)= \frac{e^{- \lambda } \lambda^{0}}{0!} \\\\\to \lambda = 1.12 \\\\=e^{-1.12}\\\\= 0.32628 \\[/tex]

You must find it: [tex]P(X \leq 2)[/tex]

[tex]\to P( X \leq 2) = P(Y=0) +P(Y=1)+P(Y=2) \\\\= \sum_{x= 0}^{2} P(Y=y) \\\\= \sum_{x= 0}^{2} \frac{e^{- \lambda} \lambda^{y} }{y!} \\\\= e^{-1.12}\sum_{x= 0}^{2} \frac{ 1.27^{y} }{y!} \\\\= 0.896356[/tex]

Comparing [a], [b], for the ford car and [b] and [c] for Toyot effectiveness  

Car, its probability that less faults with Toyota car are strong, that's why it's better