Answer:
Part A
71°
Part B
The ladder is been used safely
Step-by-step explanation:
Part A
We solve the above question using Trigonometric function of Cosine
cos x = Adjacent/Hypotenuse
Adjacent = The distance between the house and the bottom of the ladder = 4 feet
Hypotenuse = Length of the ladder = 12 feet
x = Angle
Hence:
cos x = 4/12
cos x = 1/3
x = arc cos (1/3)
x = 70.528779366°
Approximately to the nearest degree
= 71°
Part B
According to the manufacturer, if the angle the ladder forms with the ground, x, is between 70° and 75°, then it meets safety standards. Is this ladder being used safely?
Angle x = 71°
Therefore, the ladder is been used safely
The nearest tenth is
129.6
Answer:
-6a-8b+2
Step-by-step explanation:
=-2*3a+(-2)*4b+(-2)*(-1)=-6a-8b+2
Answer:
The answer is below
Step-by-step explanation:
The time between arrivals of small aircraft at a county airport is exponentially distributed with a mean of one hour. Round the answers to 3 decimal places.
(a) What is the probability that more than three aircraft arrive within an hour?
(b) If 30 separate one-hour intervals are chosen, what Is the probability that no interval contains more than three arrivals?
(c) Determine the length of an interval of time (in hours) such that the probability that no arrivals occur during the interval is 0.1.
Solution:
a) A poisson distribution is given by the formula:

λ = 1 hour
Therefore:
P(X > 3) = 1 - P(X < 3) = 1 - [P(X = 0) + P(X = 1) + P(X = 2) + P(x = 3)]




P(X > 3) = 1 - [0.3679+0.3679 + 0.1839 + 0.0613] = 0.019
b) Assuming 30 1 hour intervals, hence:
![P(X \leq 3)^{30}=[1-P(X\geq 30)]^{30}=(1-0.019)^{30}=0.5624](https://tex.z-dn.net/?f=P%28X%20%5Cleq%203%29%5E%7B30%7D%3D%5B1-P%28X%5Cgeq%2030%29%5D%5E%7B30%7D%3D%281-0.019%29%5E%7B30%7D%3D0.5624)
c) mean = 1 hour
mean = 1 / λ
1 = 1 / λ
λ = 1
The cumulative distribution function of a continuous variable is:


What kind of subject do you tutor in ? c: