FIRST ASSIGNMENT

ANS1. When applied to sample data, the population variance formula is a biased estimator of the population variance: it tends to underestimate the amount of variability. So ultimately we divide the sum of squared deviations from the sample mean by the number of degrees of freedom.

ANS2.The main difference between stratified sampling and cluster sampling is that with cluster sampling, you have natural groups separating your population.In stratified sampling, a sample is drawn from each strata (using a random sampling method like simple random sampling or systematic sampling).

ANS3. TOTAL NUMBER OF SAMPLES THAT CAN BE CREATED OUT OF POPULATION OF SIZE n is n!

ANS4. PROBABILITY= 4C2/52C2

ANS5. PROBABILITY = 6/6^2

ANS6. TO MAINTAIN THE CONSISTENCY OF THE UNITS