3. a) If the variance of a normal population is 4, what is the probability that the variance of a random sample of size 10 exceeds 6.526? Find the probability using R. Copy and paste the code and the probability.

b) If two independent random samples are obtained from normal populations with equal variance, and the sample sizes are 10 and 13 respectively, use R to find P( < 2). Copy and paste the code and the probability into your paper.