The miles-per-gallon rating of passenger cars is a normally distributed random variable with a mean of 33.8 mpg and a standard deviation of 3.5 mpg. a) What is the probability that a randomly selected passenger car gets more than 37.3 mpg

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Answer:

The probability that a randomly selected passenger car gets more than 37.3 mpg is 0.1587.

Step-by-step explanation:

Let the random variable X represent the miles-per-gallon rating of passenger cars.

It is provided that [tex]X\sim N(\mu=33.8,\ \sigma^{2}=3.5^{2})[/tex].

Compute the probability that a randomly selected passenger car gets more than 37.3 mpg as follows:

[tex]P(X>37.3)=P(\frac{X-\mu}{\sigma}>\frac{37.3-33.8}{3.5})[/tex]

                   [tex]=P(Z>1)\\\\=1-P(Z<1)\\\\=1-0.84134\\\\=0.15866\\\\\approx 0.1587[/tex]

Thus, the probability that a randomly selected passenger car gets more than 37.3 mpg is 0.1587.