Basics of Probability and Statistics Week 1 Challenge

Ans 1 Population variance refers to the value of variance that is calculated from population data, and sample variance is the variance calculated from sample data. Due to this value of denominator in the formula for variance in case of sample data is 'n-1', and it is 'n' for population data.

Ans 2 In Cluster Sampling, the sampling is done on a population of clusters therefore, cluster/group is considered a sampling unit. In Stratified Sampling, elements within each stratum are sampled. In Cluster Sampling, only selected clusters are sampled. In Stratified Sampling, from each stratum, a random sample is selected.

Ans 3 n!

Ans 4 1/13*1/13=1/169

Ans 5 1/6

Ans 6 To Maintain the consistancy with respect to units