<span>E[Y] = 0.4·1 + 0.3·2 + 0.2·3 + 0.1·4 = 2
E[1/Y] =0.4·1/1 + 0.3·1/2 + 0.2·1/3 + 0.1·1/4 = 0.4 + 0.15 + 0.0666 + 0.025?0.64
V[Y] =E[Y2]-E[Y]2= (0.4)·12+(0.3)·22+(0.2)·32+(0.1)·42-22= 0.4+1.2+1.8+1.6-4= 5-4 = 1</span>
I believe that the best answer among the choices provided by the question is <span>2) figure that has 3 or more unequal length sides.</span>
Hope my answer would be a great help for you. If you have more questions feel free to ask here at Brainly.
A garph y=2 represents a line parallel to the x axis with the y coordinate equal to 2.
The point which lies on the y=2 graph has its y coordinate equal to 2.
In the given options, (3,2) is the coordinate with the y coordinate equal to 2.
Hence, (3,2) lies on the graph of y = 2.
Option (D) is the answer.
Answer:
27.5 minutes
Step-by-step explanation:
Using,
R/R' = 2ᵃ/ᵇ------------------ Equation 1
From the equation,
R = mass of Element X before radioactive decay, R' = mass of element X after radioactive decay, a = Time taken, b = half life.
Given: R = 870 grams, R' = 154 grams, b = 11 minutes.
Substitute these values into equation 1
870/154 = 2ᵃ/¹¹
(870/154)¹¹ = 2ᵃ
Solve for a
2ᵃ = (5.649)¹¹
2ᵃ = 187061.26
Taking the logarithm of both side,
Log2ᵃ = Log(187061.26)
⇒ a = log(187061.26)/log2
a = 8.272/0.301
a = 27.5 minutes
