Answer:
a. See attachments
B. 163630.2ft
C. 147056.70ft
D. 49205.4ft
Step-by-step explanation:
Check attachments for details
Angle a.. Angle of dep to beginning of runway
Angle b... Angle of del to end of runway
AD... Altitude of plane
DB..... Ground distance before touch down
AC... Air distance travelled until touch down on the near end of runway
Answer:
a)
And we can find this probability using the normal standard distribution or excel and we got:
b)
And we can find this probability using the complement rule and normal standard distribution or excel and we got:
c)
And if we solve for a we got
So the value of height that separates the bottom 75% of data from the top 25% is 46.033.
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 heights of a population, and for this case we know the distribution for X is given by:
Where and
Part a
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 normal standard distribution or excel and we got:
Part b
And we can find this probability using the complement rule and normal standard distribution or excel and we got:
Part c
For this part we want to find a value a, such that we satisfy this condition:
(a)
(b)
Both conditions are equivalent on this case. We can use the z score again in order to find the value a.
As we can see on the figure attached the z value that satisfy the condition with 0.75 of the area on the left and 0.25 of the area on the right it's z=0.674. On this case P(Z<0.674)=0.75 and P(z>0.674)=0.25
If we use condition (b) from previous we have this:
But we know which value of z satisfy the previous equation so then we can do this:
And if we solve for a we got
So the value of height that separates the bottom 75% of data from the top 25% is 46.033.