Referring back to the Texas Department of Insurance data on closed claims for medical malpractice liability insurance presented in Problem 5, we wish to see if medical malpractice was more risky to the insurer during the 1998–2001 period than it was in the 1994–1997 period. The data from 1994 until 2001 was:

Injury year Estimated # claims Estimated $ per claim

1994 1021 $415,326.26

1995 1087 $448,871.57

1996 1184 $477,333.66

1997 1291 $490,215.19

1998 1191 $516,696.63

1999 1098 $587,233.93

2000 1055 $536,983.82

2001 1110 $403,504.39

a. Calculate the standard deviation in the estimated payment per claim for medical malpractice insurance in Texas over the four-year period 1994–1997.