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:
z=14.73
p=0.000
for 99% confidence level the null hypothesis is rejected, thus majority of us adults would not bothered if the NSA collected personal records.
Step-by-step explanation:
: Half of US adults would not bothered if the NSA collect records of personal telephone calls
: Majority of the adults would not bothered if the NSA collect records of personal telephone calls
According to the sample, z-value can be found using the formula:
z=
where
- X is the adults, who would not be bothered in the survey (397)
- M is the mean of the distribution of null hypothesis (257)
- n is the sample size (514)
- p is the proportion of the sample, who said they would not bothered (
≈ 0.77)
Putting these numbers in the formula,
z=14.73 and corresponding p value is p≈0.000
Since p<0.01, for 99% confidence level we reject the null hypothesis, thus majority of us adults would not bothered if the NSA collected personal records.
Answer:
y = 0.15x+77 is the equation linear connecting total cost y and miles driven x
Step-by-step explanation:
Given that the leasing company charged a flat rental fee for the week, plus a charge for each mile driven.
Let flat rental fee be c and cost per mile driven = m and miles driven = x
Total cost =y
Then y = mx+C is the linear equation.
to find m and c, we use the fact that y =110.30 when x = 222
i.e. 110.30 = c+222x
and similarly 99.05 = c+147x
Subtract to eliminate c
11.25 = 75 x
0.15 =x
Substitute in I equation
110.30 = c+222(0.15)
c = 77
Hence y = 0.15x+77 is the equation linear connecting total cost y and miles driven x