Answer:
The probability of Type I error is = 0.10185.
Step-by-step explanation:
Solution:-
The type I - error is defined as the probability of rejecting Null hypothesis defined by Alternate hypothesis:
Ha : X ≥ 8
Where,
X : Denote the number of cars crash with no visible damage
The random variate "X" is defined by binomial distribution:
X ~ B ( n = 20 , p = 0.25 )
- The probability of Type I error:
P (Type I error ) = P ( Reject Null hypothesis )
= P ( X ≥ 8 )
- The probability mass function of binomial random variate "X" is given:
![P ( X = x ) = nCr (p)^r * (1-p)^(^n^-^r^)\\P ( X \geq 8 ) = 1 - P ( X < 8 )\\\\P ( X \geq 8 ) = 1 - [ P ( X = 0 ) + P ( X = 1 ) + P ( X = 2 ) + P ( X = 3 ) + P ( X = 4 ) + P ( X = 5 ) + P ( X = 6 ) + P ( X = 7 ) ]](https://tex.z-dn.net/?f=P%20%28%20X%20%3D%20x%20%29%20%3D%20nCr%20%28p%29%5Er%20%2A%20%281-p%29%5E%28%5En%5E-%5Er%5E%29%5C%5CP%20%28%20X%20%5Cgeq%20%208%20%29%20%3D%201%20-%20P%20%28%20X%20%3C%208%20%29%5C%5C%5C%5CP%20%28%20X%20%5Cgeq%20%208%20%29%20%3D%201%20-%20%5B%20P%20%28%20X%20%3D%200%20%29%20%2B%20P%20%28%20X%20%3D%201%20%29%20%2B%20P%20%28%20X%20%3D%202%20%29%20%2B%20P%20%28%20X%20%3D%203%20%29%20%2B%20P%20%28%20X%20%3D%204%20%29%20%2B%20P%20%28%20X%20%3D%205%20%29%20%2B%20P%20%28%20X%20%3D%206%20%29%20%2B%20P%20%28%20X%20%3D%207%20%29%20%5D)
![P ( X \geq 8 ) = 1 - [ (0.75)^2^0 + 20(0.25)*(0.75)^1^9 + 20C2(0.25)^2*(0.75)^1^8 +\\\\ 20C3(0.25)^3*(0.75)^1^7 + 20C4(0.25)^4*(0.75)^1^6 + 20C5(0.25)^5*(0.75)^1^5\\\\ + 20C6(0.25)^6*(0.75)^1^4 + 20C7(0.25)^7*(0.75)^1^3 ] \\\\\\P ( X \geq 8 ) = 1 - [ 0.00317 + 0.02114 + 0.06694 + 0.13389 + 0.18968 + 0.20233\\\\+ 0.16860 + 0.11240]\\\\P ( X \geq 8 ) = 1 - 0.89815 = 0.10185](https://tex.z-dn.net/?f=P%20%28%20X%20%5Cgeq%20%208%20%29%20%3D%201%20-%20%5B%20%280.75%29%5E2%5E0%20%2B%2020%280.25%29%2A%280.75%29%5E1%5E9%20%2B%2020C2%280.25%29%5E2%2A%280.75%29%5E1%5E8%20%2B%5C%5C%5C%5C%20%20%20%20%20%20%20%20%20%20%20%20%20%20%2020C3%280.25%29%5E3%2A%280.75%29%5E1%5E7%20%2B%2020C4%280.25%29%5E4%2A%280.75%29%5E1%5E6%20%2B%2020C5%280.25%29%5E5%2A%280.75%29%5E1%5E5%5C%5C%5C%5C%20%2B%2020C6%280.25%29%5E6%2A%280.75%29%5E1%5E4%20%2B%2020C7%280.25%29%5E7%2A%280.75%29%5E1%5E3%20%5D%20%5C%5C%5C%5C%5C%5CP%20%28%20X%20%5Cgeq%20%208%20%29%20%3D%201%20-%20%5B%200.00317%20%2B%200.02114%20%2B%200.06694%20%2B%200.13389%20%2B%200.18968%20%2B%200.20233%5C%5C%5C%5C%2B%200.16860%20%2B%200.11240%5D%5C%5C%5C%5CP%20%28%20X%20%5Cgeq%20%208%20%29%20%3D%201%20-%200.89815%20%3D%200.10185)
Answer: The probability of Type I error is = 0.10185.