Chapter 3: Estimation

Question 1

Chebychev’s rule

Answer 1

For any data set and any real number k which is greater than or equal to 1, at least (1-1/k^2) *100% of the measurements are within k standard deviations on either side of the mean.

Question 2

Empirical rule

Answer 2

For any data set having roughly a mound-shaped and symmetric distribution (bell-shaped data):
- approx 68% of obs lie within 1 SD of either side of the mean
- approx 95% of obs lie within 2 SD of either side of the mean
- approx 99.7% of obs lie wihtin 1 SD of the mean

Question 3

When to use empirical vs chebychevs rule?

Answer 3

CHebychev’s rule works for any set of measurements while empirical works best for bell shaped

Question 4

What is an interval estimator?

Answer 4

a formula that tells us how to use sample data to calculate an interval of values that estimates a population parameter.

Question 5

What is the confidence coefficient?

Answer 5

the probability that an interval estimator encloses the population parameter in repeated samples

Question 6

What is the confidence level?

Answer 6

the confidence coefficient expressed as a percentage.

Question 7

What is a critical value?

Answer 7

a number that depends on our sampling distribution and our level of confidence