Answer:
V(X)= 39.10
V(Y)= 40
Step-by-step explanation:
Given that
Total number of student = 140 
Bus A - 31
Bus B- 43
Bus C- 27
Bus D- 39
The probability that a student was on the bus is proportional to the number of student. Eg 31/140 in bus A, 43/140 on bus B, ...
E(X) = (31*31/140) + (43*43/140)  + (27*27/140) + (39*39/140) 
=  35.5

V(X)= 39.10
The bus driver have  1/4 probability on being on any of the buses. 
E(Y) = 140/4 = 35

V(Y)= 40
 
        
             
        
        
        
Answer:
20 units
Step-by-step explanation:
The polygon has 4 vertices as indicated by the 4 coordinate points given.
(3, 1) and (8, 1) is a horizontal side of length 8 - 3 = 5
Similarly
(3, 6) and (8, 6) is the opposite horizontal side of length 8 - 3 = 5
Points (3, 1) and (3, 6) is a vertical side of length 6 - 1 = 5
(8, 1) and (8, 6) is the opposite side of length 6 - 1 = 5
The polygon is therefore a square of side 5 units.
Perimeter = 4 × 5 = 20 units
 
        
             
        
        
        
Answer:

Step-by-step explanation:
let base be x ft. then the height is 3x+4

 
        
                    
             
        
        
        
There are 50 States so if the no. of states in which company A operates is 36 then the no. of states it does operate = 50 - 36 = <em><u>14</u></em> 
14/50 = 7/25 states does not have a store operated by company A 
 
        
             
        
        
        
P(B | A) = probability of B given A
P(B | A) = P(B and A) / P(A)
thus
P(new oil filter | oil change) = P(both) / P(oil change)
= 0.14 / 0.25
(b) = 0.14 / 0.4