3. A study was conducted to investigate whether elevated blood pressure is associated with maculopathy, and 100 people aged between 50 and 60 years with maculopathy were enrolled. The mean systolic blood pressure (SBP, mmHg) was 147 and the standard deviation was 27.

(a) Find the 95% CI for the population mean SBP in people with maculopathy.

(b) Find the 95% CI for the population variance of SBP in people with maculopathy.