Answer:
19. x = 65
20. x = 12
21. x = 35, y = 85
Step-by-step explanation:
19. 2x -10 = 120
2x (-10 + 10) = (120 +10)
2x/2 = 130/2
x = 65
20. 2x + 4x + 108 = 180
6x + (108 - 108) = (180 - 108)
6x/6 = 72/6
x = 12
21. 2x + 25 = 3x - 10
2x + (25 - 25) = 3x (- 10 - 25)
(2x - 3x) = (3x - 3x) - 35
-x/-1 = -35/-1
x = 35
3x - 10 + y = 180
3(35) - 10 + y = 180
105 - 10 + y = 180
(95 - 95) + y = (180 - 95)
y = 85
Answer:
0.4
Step-by-step explanation:
2/5 (2 divided by 5)
Answer:
see below
Step-by-step explanation:
A = pi r^2
If they have the same radius they have the same area
A two circles = pi r^2 +pi r^2
= 2 pi r^2
If we double the radius
A = pi (2r)^2
= pi 4r^2
The combined area of two circles is 1/2 the area as the area of a circle with twice the radius.
Answer:
The expected participation rate is 0.637.
The standard error is 0.04397
Step-by-step explanation:
For each working age people asked, there are only two possible outcomes. Either they are in the labor force, or they are not. This means that we can solve this problem using binomial distribution probability concepts.
Binomial probability:
Expected value for the participation rate: The expected value is the probability of a success. In this problem, a success is a working age people being in the labor force. 63.7% of them are. So
. This means that the expected participation rate is 0.637.
Standard error for the participation rate:
The standard error is given by the following formula:
.
In this problem, 120 people are asked, so 
.
So the standard error is 0.04397