Lou is reviewing chart data from patients with multiple sclerosis (MS). In one part of this study, Lou is looking at whether this group of MS patients is at a higher risk for other chronic diseases. The patients' levels of low-density lipoprotein (LDL) have been collected via blood draws. High serum concentrations of LDL are associated with an elevated risk of cardiovascular disease (CVD). From this sample, the mean concentration was 219 mg/dL with a standard deviation (sigma ) of 50 mg/dL Assuming that LDL concentration has a normal distribution in MS patients, answer the following questions.

What is the variance of LDL in this group?