Could you advise me on the answer and explanation for this question please?

Question 1 A company wants to investigate the variation in the number of insurance claims made each week. From a random sample of six weeks the total number of claims each week is found to be Week 2 4 5 6 Insurance claims 75 88 90 86 60 97 Use this sample to estimate the standard deviation of insurance claims per week for all weeks. a) 11.7 b) 10.05 c) 6.84 d) 13.20 e) 15.52