Answer:
12
Step-by-step explanation:
A 2 - sided counter ; (red, yellow)
A spinner (1,2,3,4,5,6)
Number of trials = 80
P(red and number > 3) :
P(red) = 1/2 ;
P(number >3) : numbers greater Than 3 = (4, 5, 6)
Hence, P(number <3) = 3 /6 = 1/2
Theoretical probability = 1/2 *1/2 = 1/4
Expected number of outcomes :
1/4 * number of trials
1/4 * 80 = 20
Experimental outcome :
Relative frequency = number of outcomes / number of trials
Relative frequency = 2/5
Hence,
2/5 = number of outcomes / 80
Cross multiply :
160 = number of outcomes * 5
Number of outcomes = 160 /5 = 32
Actual outcomes = 32
Difference between actual and expected :
32 - 20 = 12
The parametric equations for x and y describe a circle of radius 10 m, so the length of the base of the fence is the length of the circumference of a circle of radius 10 m. The formula for that circumference (C) is ...
... C = 2πr
... C = 2π·(10 m) = 20π m
The height as a function of angle (t) is found by substituting for x and y.
... h(t) = h(x(t), y(t)) = 4 + 0.01·((10cos(t))²-)10sin(t))²) = 4+cos(2t)
The average value of this over the range 0 ≤ t ≤ 2π is 4, since the cosine function has two full cycles in that range, and its average value over a cycle is zero.
Thus, the area of one side of the fence is that of a rectangle 20π m long and 4 m wide. That will be
... (20π m)·(4 m) = 80π m²
The amount of paint required to cover both sides of the fence is
... 2×(80π m²)×(1 L)/(10 m²) = 16π L ≈ 50.3 L
_____
You can work out the integral for area as a function of t. When you do, you will find it gives this same result.
The picture below has both of the answers to your problem.
Hello,
505/1 000 = ( 505 / 5 ) / ( 1 000 / 5 ) = 101/200
Bye :)
