Answer:
a) 
b) 
c)
And we can find this probability using the complement rule and the normal standard distribution or excel and we got:
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".
Part a
Let X the random variable that represent the amount of money of a population of interet, and we know the following info:
Where
and
We can assume that the sample size is large and the estimators can be used as a good description for the parameters 
The z score for 40000 would be:

Part b
The z score for 50000 would be:

Part c
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability using the complement rule and the normal standard distribution or excel and we got:
Answer:
-1
Step-by-step explanation:
Since 34 is an even number, we can factor a 2 out of the exponent of your problem, like this:
i34=(i2)17.
But, i2=-1, so your problem becomes:
-117.
This means, multiply -1 by itself 17 times, to get -1
(Remember, -1 raised to an odd power is always -1, so -117=-1.)
The final answer is:
i34=-1
Answer:
No. It is an obtuse triangle.
Step-by-step explanation:
If c^2>a^2+b^2, then the triangle is obtuse. Since 24^2 + 7^2 is 625, and the square root of 625 is 25, that means 26>25. This proves that the triangle is obtuse.
Subtract 9x from 23x yields 14x. This was done by subtracting algebraically the variables.