Respuesta :
Answer:
Standard Deviation = 0.032 or 3.2%
Therefore, Option  C) 3.22 percent is the correct answer
Explanation:
Given the data in the question;
lets make a table;
year   market    Treasury bills    Risk        deviation       square of
      returns       returns     premium     from mean      deviation
        A           B          (A - B)     Avg - (A - B)    (Avg-(A-B))²
1 Â Â Â Â Â Â 7.2% Â Â Â Â Â Â Â Â 3.4% Â Â Â Â Â Â Â Â 3.8% Â Â Â Â Â Â -0.0195 Â Â Â Â Â Â Â 0.0004
2 Â Â Â Â Â Â 5.8% Â Â Â Â Â Â Â Â 3.3% Â Â Â Â Â Â Â Â 2.5% Â Â Â Â Â Â -0.0325 Â Â Â Â Â Â Â 0.0011
3 Â Â Â Â Â Â 11.2% Â Â Â Â Â Â Â Â 4.1% Â Â Â Â Â Â Â Â 7.1% Â Â Â Â Â Â Â 0.0135 Â Â Â Â Â Â Â 0.0002
4 Â Â Â Â Â Â 13.6% Â Â Â Â Â Â Â 4.0% Â Â Â Â Â Â Â Â 9.6% Â Â Â Â Â Â 0.0385 Â Â Â Â Â Â Â 0.0015
sum(∑)                           23%                     0.0032
Average Avg = ∑(A-B) /n = 23/4 = 5.75%  Â
so Variance = ∑(Avg-(A-B))² / n-1 = 0.0032 / (4-1) = 0.0032 / 3 = 0.0010   Â
Standard Deviation = √variance = √0.0010 = 0.0316 ≈ 0.032 or 3.2%
Therefore, Option  C) 3.22 percent is the correct answer