Suppose that the distance of fly balls threw (hit) to the outfield (in baseball) is normally distributed with a mean of 246 feet and a standard deviation of 39 feet. Let X be the distance in feet for a fly ball. Round all answers to two decimal places.

A. X ~ N( ____ , _____ )
B. Find the probability that a randomly hit fly ball travels less than 200 feet.
C.Find the 70th percentile for the distribution of fly balls.

Respuesta :

Answer:

a) [tex]X\sim(246,1521)[/tex]

b) 0.1191

c) [tex]P_{70}=266.44[/tex]

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 246 feet

Standard Deviation, σ = 39 feet

We are given that the distribution of distance of fly balls is a bell shaped distribution that is a normal distribution.

a) Distribution of X

Let X be the distance in feet for a fly ball. Then,

[tex]X\sim (\mu, \sigma^2)\\X\sim(246,39^2)\\X\sim(246,1521)[/tex]

b) Probability that a randomly hit fly ball travels less than 200 feet.

[tex]P( x < 200) = P( z < \displaystyle\frac{200 - 246}{39}) = P(z < -1.1794)[/tex]

Calculation the value from standard normal z table, we have,  

[tex]P(x < 200) = 0.1191[/tex]

c) 70th percentile for the distribution of fly balls.

We have to find the value of x such that the probability is 0.7

[tex]P( X < x) = P( z < \displaystyle\frac{x - 246}{39})=0.7[/tex]  

Calculation the value from standard normal z table, we have,  

[tex]\displaystyle\frac{x - 246}{39} = 0.524\\\\x = 266.436\approx 266.44[/tex]  

The 70th percentile for the distribution of fly ball is 266.44 feet.