Answer:
a) 0.3874
b) 0.3874
c) 0.1722
d) Mean and Standard Deviation = 0.9
Step-by-step explanation:
This is binomial distribution problem that has formula:
Here p is probability of success = 10% = 0.1
q is probability of failure, that is 90% = 0.9
n is total number, which is 9, so n = 9
a)
The probability that none requires warranty is r = 0, we substitute and find:
Probability that none of these vehicles requires warranty service is 0.3874
b)
The probabilty exactly 1 needs warranty would change the value of r to 1. Now we use the same formula and get our answer:
This probability is also the same.
Probability that exactly one of these vehicles requires warranty is 0.3874
c)
Here, we need to make r = 2 and put it into the formula and solve:
Probability that exactly two of these vehicles requires warranty is 0.1722
d)
The formula for mean is
Mean = n * p
The formula for standard deviation is:
Standard Deviation =
Hence,
Mean = 9 * 0.1 = 0.9
Standard Deviation =