Answer:
36.58% probability that one of the devices fail
Step-by-step explanation:
For each device, there are only two possible outcomes. Either it fails, or it does not fail. The probability of a device failling is independent of other devices. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
A total of 15 devices will be used.
This means that 
Assume that each device has a probability of 0.05 of failure during the course of the monitoring period.
This means that 
What is the probability that one of the devices fail?
This is 


36.58% probability that one of the devices fail
Answer:
8,13
Step-by-step explanation:
The pattern in +5 so 3+5=8, and 8+5=13
Answer: D) 99 Points
Step-by-step explanation: Theresa earned scores of 88 points, 84 points, 88 points, and 91 points on four tests
Therefore the totals points are 351
351 is her total score for 4 tests, if she gets an average score of 90 on her fifth test then all we have to do is:
5 x 90 = 450 (The 5 being her fifth test)
450-351 = 99
Option D
Answer:
4
Step-by-step explanation:
2+2 =4