Answer: 12
Step-by-step explanation:
Answer:
And if we solve for a we got
And the limits for this case are: (214.4; 295.4)
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the annual precipitation of a population, and for this case we know the distribution for X is given by:
Where
and
The confidence level is 95.44 and the signficance is
and the value of
. And the critical value for this case is 
Using this condition we can find the limits
And if we solve for a we got
And the limits for this case are: (214.4; 295.4)
Answer:
25% probability that all three residents will choose the same plumbe
Step-by-step explanation:
For each resident, there are only two possible outcomes. Either they choose the first plumbe, or they choose the second. The plumbers are chosen independent of each other. 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.
Each resident randomly chooses one of the two plumbers.
This means that 
Three residents:
This means that 
What is the probability that all three residents will choose the same plumb
This is P(X = 0)(all choose the second pumble) or P(X = 3)(all choose the first pumble). So

25% probability that all three residents will choose the same plumbe
2(2x-4) because when you multiply 2 x 2x it equals 4x. When you multiply 2 x 4 it equals 8. Leaving you with 4x-8
Answer:
54779098.9847
Step-by-step explanation:
You add them together