Basics of Probability and Statistics Week 1 Challenge

1. There is a possibility that sample variance is greater than population variation and to compensate for this error we use the n-1 in the denominator when we calculate sample variance.

2. In stratified sampling population is divided into subgroups or strata based on certain characteristics that are relevant to the study like age, gender, income, and education level.

In clustered sampling population is divided into groups or clusters.

3. The number of samples that can be created from population size n depends on the sampling method, whether or not sampling is done with or without replacement.

4. total 52 cards, 4 jack

to draw first jack = 4/52 second jack = 3/51

probability = (4/52)*(3/51) = (1/13)*(1/17) = 1/221

5. 2 dice total probability 36

probability for both numbers is the same (1,1),(2,2),(3,3).(4,4),(5,5),(6,6) = 6/36 = 1/6

6. Standard deviation is more sensitive to outliers than variance, less affected by extreme values.