Answer
a) y | p(y)
25 | 0.8
100 | 0.15
300 | 0.05
E(y) = ∑ y . p(y)
E(y) = 25 × 0.8 + 100 × 0.15 + 300 × 0.05
E(y) = 50
average class size equal to E(y) = 50
b) y | p(y)
25 | 
100 | 
300 | 
E(y) = ∑ y . p(y)
E(y) = 25 × 0.4 + 100 × 0.3 + 300 × 0.3
E(y) = 130
average class size equal to E(y) = 130
c) Average Student in the class in a school = 50
Average student at the school has student = 130
Answer:
14
Step-by-step explanation:
Answer:
5
Step-by-step explanation:
4p-pq=4.5-3.5=20-15=5
Answer:
see explanation
Step-by-step explanation:
Given that the the difference of cubes is
a³ - b³ = (a - b)(a² + ab + b²)
Given
64
- 27 ← a difference of cubes
with a = 4x² and b = 3, thus
= (4x²)³ - 3³
= (4x² - 3)(16
+ 12x² + 9) ← in factored form
Answer:
x = 4 and y = - 5
Step-by-step explanation:
note that the product of a complex number and it's conjugate is real
That is
(a + bi)(a - bi) where a, b are real
= a² - abi + abi - b²i²
= a² + b² ← a real number
For (4 + 5i)(x + yi) to be real
we require (x + yi) to be the conjugate of 4 + 5i , that is 4 - 5i
(4 + 5i)(4 - 5i) ⇒ x = 4 and y = - 5
