Answer:
μ ≈ 2.33
σ ≈ 1.25
Step-by-step explanation:
Each person has equal probability of ⅓.
The mean is the expected value:
μ = E(X) = ∑ X P(X)
μ = (1) (⅓) + (2) (⅓) + (4) (⅓)
μ = ⁷/₃
The standard deviation is:
σ² = ∑ (X−μ)² P(X)
σ² = (1 − ⁷/₃)² (⅓) + (2 − ⁷/₃)² (⅓) + (4 − ⁷/₃)² (⅓)
σ² = ¹⁴/₉
σ ≈ 1.25
Answer:
A) all real numbers greater than or equal to 2
Domain:
Step-by-step explanation:
The variable in the radical <em>x </em>cannot be less than 0 as that wouldn’t be defined. So, the maximum that <em>x </em>can be is 0, and . So, 0+2=2, and <em>y </em>is greater than or equal to 2.
Domain is x is greater than or equal to 0 because you cannot square a negative. So, it must not be less than 0. It could be 0 because square root of 0 is just 0.