Table 2a: Summary for the Sum of the Total_Amount (gender versus marital_status) Female Male Grand Total Divorced 505.32 505.32 Married 4354.07 19021.06 23375.13 Single 1074.22 8971.38 10045.6 Widow 151.19 151.19 Grand Total 6084.8 27992.44 34077.24 Table 2b: Summary for the Count of the Total_Amount (gender versus marital_status) Female Male Grand Total Divorced 1 1 Married 7 14 21 Single 3 4 7 Widow 1 1 Grand Total 12 18 30 Table 2c: Summary for the Variance of the Total_Amount (gender versus marital_status) Female Male Grand Total Divorced Married 397600.4597 3796370.421 2713535.577 Single 127424.6785 3315939.532 2715405.869 Widow Grand Total 266016.7452 3631348.173 2502342.468 Table 2d: Possible t-value at 95% confidence level for each customer category Female Male Grand Total Divorced Married 2.446912 2.160369 2.085963447 Single 4.302653 3.182446 2.446911851 Widow Grand Total 2.200985 2.109816 2.045229642 Based on the above tables, 2a, b, c and d, answer the following questions: The standard deviation for the total amount ($) for married customers is: a. 1647.281268 b. 1647.848861 c. 1820.972 d. 1948.428