Answer:
0.789
Step-by-step explanation:
First, find the expected value (the mean).
μ = ∑ x P(x)
μ = (0) (0.359) + (1) (0.436) + (2) (0.180) + (3) (0.025)
μ = 0.871
Next, find the variance.
σ² = ∑(x − μ)² P(x)
σ² = (0 − 0.871)² (0.359) + (1 − 0.871)² (0.436) + (2 − 0.871)² (0.180) + (3 − 0.871)² (0.025)
σ² = 0.622
Finally, find the standard deviation:
σ = √0.622
σ = 0.789
Answer:b
Step-by-step explanation:
4 just count how many are there that are between 19-21
