Carroll et al. (2005) discuss trends in serum lipids and lipoproteins for US adults for the period 1960 to 2002.

Carroll et al. (2005) discuss trends in serum lipids and lipoproteins for US adults for the period 1960 to 2002. In this study, the population mean serum total cholesterol for women aged 20 to 29 years, inclusive, for the period 1999 to 2002, inclusive, was 183 mg/dl with an assumed population standard deviation of 40.3 mg/dl. If a sample of size 961 is considered; 

What is the probability that the average woman aged 20 to 29 years for the period 1999 to 2002 has a serum total cholesterol between 160 mg/dl and 200 mg/dl.