Answer:
59 accidents were investigated.
Step-by-step explanation:
The question above is a probability question that involves 2 elements: causes of accidents.
Let
A = Alcohol
E = Excessive speed
In the question, we are given the following information:
18 accidents involved Alcohol and Excessive speed =P(A ∩ E)
26 involved Alcohol = P(A)
12 accidents involved excessive speed but not alcohol = P( E ) Only
21 accidents involved neither alcohol nor excessive speed = neither A U B
We were given P(A) in the question. P(A Only) = P(A) - P(A ∩ E)
P(A Only) = 26 - 18
= 8
So, only 8 accident involved Alcohol but not excessive speed.
The Total number of Accidents investigated = P(A Only) + P( E only) + P(A ∩ E) + P( neither A U B)
= 8 + 12 + 18 + 21
= 59
Therefore, 59 accidents were investigated.
Answer:

8,3*0,25=2,10%(2d.p)
Step-by-step explanation:
Step-by-step explanation:
The probability of success = 8/(8 + 17) = 8/25 = 0.32.
Let X be the random variable denoting the number of successes (number of times the individual won a prize) in four picks.
Hence, X ~ Bin(4, 0.32).
Thus, P(X = 1) = 
Answer:
a) 20%
b) 40%
c) Mean = 62.5 seconds; Variance = 52.083 seconds
Step-by-step explanation:
The time it takes a hematology cell counter to complete a test on a blood sample is continuously distributed over the period of 50 to 75 seconds with probability f(x) = 0.04.
a) The percentage of tests require more than 70 seconds is:

b)The percentage of tests that require less than one minute (60 seconds) is:

c) The mean and variance of a continuous distribution are determined by:

Mean = 62.5 seconds.
Variance = 52.083 seconds.