Answer: 2.28%
Step-by-step explanation:
Given: An airport find that at the present time, the mean noise level is 103 decibels and the standard deviation is 5.4 decibels.
The distribution of noise levels(x) for all jets during takeoff over the neighborhood has a normal distribution.
The probability that jets have a noise level less than 92.2 decibels when taking off over this neighborhood will be :-

Hence, the percent of these jets have a noise level less than 92.2 decibels when taking off over this neighborhood = 2.28%
Answer:
133/10
Step-by-step explanation:
divide 160 and 12 then simplify your answer
78.8 rounded to the nearest tenths is 78.8
We can not round it to the tenths because it already is rounded to the tenths.
Answer:
The approximate value of the area is 
Step-by-step explanation:
we know that
The area of the circle (landing pad) is equal to

we have

substitute

----> exact value of the area
Find the approximate value
assume 
------> approximate value of the area
Answer:
b = 55 degrees
Step-by-step explanation:
The angles 30, a, b and 45 must sum up to 180 degrees
Subtracting (30 + 45) from both sides leaves us with a + b = 105 degrees.
But b = a + 5. Substituting a + 5 in the equation above yields
a + a + 5 = 105 degrees, so that
2a = 100 degrees, and a = 50 degrees. Then b = a + 5, or b = 55 degrees.