36 is 75% of 48 , so there was 48 questions .
Answer:
μ ≈ 2.33
σ ≈ 1.25
Step-by-step explanation:
Each person has equal probability of ⅓.
![\left[\begin{array}{cc}X&P(X)\\1&\frac{1}{3}\\2&\frac{1}{3}\\4&\frac{1}{3}\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7DX%26P%28X%29%5C%5C1%26%5Cfrac%7B1%7D%7B3%7D%5C%5C2%26%5Cfrac%7B1%7D%7B3%7D%5C%5C4%26%5Cfrac%7B1%7D%7B3%7D%5Cend%7Barray%7D%5Cright%5D)
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
The 5th term would be 18. Since you are adding by four each time, the fourth term or t(4) would be 14. Adding four more would equal 18, which is the fifth term.
Answer: Imma go with B
Step-by-step explanation: