If they're asking the distance between the tree and the man's shadow, that would be 12ft and if they're asking the distance between the tree and the actually man, that would be 15ft :).
Answer:
The amount invested at Investment A must be greater than or equal to $2,750
The amount invested at Investment B must be less than or equal to $2,250
Step-by-step explanation:
Let
x -----> the amount invested at Investment A yields 5%
y -----> the amount invested at Investment B yields 8%
we know that
-----> equation A

-----> inequality B

-----> inequality C
-----> inequality D
Substitute equation A in the inequality D and solve for y
Multiply by 2 both sides
Multiply by -1 both sides
Adds y both sides
adds 10,000 both sides
Divide by 3 both sides
-----> inequality E
therefore
<em>Solve for y</em>
we have
-----> inequality C
-----> inequality E
The solution of inequality C and inequality E is
For y=2,250
x=5,000-y ----> x=5,000-2,250=2,750
so
-----> inequality F
<em>Solve for x</em>
we have
-----> inequality B
-----> inequality F
The solution of inequality B and inequality F is

therefore
The amount invested at Investment A must be greater than or equal to $2,750
The amount invested at Investment B must be less than or equal to $2,250
Answer:
a) 

And we can use the complement rule and we got:


And replacing we got:

b) 

And we can use the complement rule and we got:


And replacing 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".
Solution to the problem
Let X the random variable that represent the length of time waiting to be seated of a population, and for this case we know the distribution for X is given by:
Where
and
Part a
For this cae we want to find this probability:

And if we use the conditional probability formula we got:

We can solve the problem using the z score formula given by:



And we can use the complement rule and we got:


And replacing we got:

Part b

We can solve the problem using the z score formula given by:



And we can use the complement rule and we got:


And replacing we got:
