Answer:
(a) The probability density function of <em>X</em> is:
![f_{X}(x)=\frac{1}{b-a};\ a](https://tex.z-dn.net/?f=f_%7BX%7D%28x%29%3D%5Cfrac%7B1%7D%7Bb-a%7D%3B%5C%20a%3CX%3Cb%2C%5C%20a%3Cb)
(b) The value of P (129 ≤ X ≤ 146) is 0.3462.
(c) The probability that a randomly selected flight between the two cities will be at least 3 minutes late is 0.4327.
Step-by-step explanation:
The random variable <em>X</em> is defined as the flight time between the two cities.
Since the random variable <em>X</em> denotes time interval, the random variable <em>X</em> is continuous.
(a)
The random variable <em>X</em> is Uniformly distributed with parameters <em>a</em> = 10 minutes and <em>b</em> = 154 minutes.
The probability density function of <em>X</em> is:
![f_{X}(x)=\frac{1}{b-a};\ a](https://tex.z-dn.net/?f=f_%7BX%7D%28x%29%3D%5Cfrac%7B1%7D%7Bb-a%7D%3B%5C%20a%3CX%3Cb%2C%5C%20a%3Cb)
(b)
Compute the value of P (129 ≤ X ≤ 146) as follows:
Apply continuity correction:
P (129 ≤ X ≤ 146) = P (129 - 0.50 < X < 146 + 0.50)
= P (128.50 < X < 146.50)
![=\int\limits^{146.50}_{128.50} {\frac{1}{154-102}} \, dx](https://tex.z-dn.net/?f=%3D%5Cint%5Climits%5E%7B146.50%7D_%7B128.50%7D%20%7B%5Cfrac%7B1%7D%7B154-102%7D%7D%20%5C%2C%20dx)
![=\frac{1}{52}\times \int\limits^{146.50}_{128.50} {1} \, dx](https://tex.z-dn.net/?f=%3D%5Cfrac%7B1%7D%7B52%7D%5Ctimes%20%5Cint%5Climits%5E%7B146.50%7D_%7B128.50%7D%20%7B1%7D%20%5C%2C%20dx)
![=\frac{1}{52}\times (146.50-128.50)](https://tex.z-dn.net/?f=%3D%5Cfrac%7B1%7D%7B52%7D%5Ctimes%20%28146.50-128.50%29)
![=0.3462](https://tex.z-dn.net/?f=%3D0.3462)
Thus, the value of P (129 ≤ X ≤ 146) is 0.3462.
(c)
It is provided that a randomly selected flight between the two cities will be at least 3 minutes late, i.e. <em>X</em> ≥ 128 + 3 = 131.
Compute the value of P (X ≥ 131) as follows:
Apply continuity correction:
P (X ≥ 131) = P (X > 131 + 0.50)
= P (X > 131.50)
![=\int\limits^{154}_{131.50} {\frac{1}{154-102}} \, dx](https://tex.z-dn.net/?f=%3D%5Cint%5Climits%5E%7B154%7D_%7B131.50%7D%20%7B%5Cfrac%7B1%7D%7B154-102%7D%7D%20%5C%2C%20dx)
![=\frac{1}{52}\times \int\limits^{154}_{131.50} {1} \, dx](https://tex.z-dn.net/?f=%3D%5Cfrac%7B1%7D%7B52%7D%5Ctimes%20%5Cint%5Climits%5E%7B154%7D_%7B131.50%7D%20%7B1%7D%20%5C%2C%20dx)
![=\frac{1}{52}\times (154-131.50)](https://tex.z-dn.net/?f=%3D%5Cfrac%7B1%7D%7B52%7D%5Ctimes%20%28154-131.50%29)
![=0.4327](https://tex.z-dn.net/?f=%3D0.4327)
Thus, the probability that a randomly selected flight between the two cities will be at least 3 minutes late is 0.4327.