Estimators and Estimates(Udemy Statistics for Data Science and Business Analysis) Flashcards
How are confidence intervals and point estimates related
Point estimates are located exactly in the center of confidence intervals
Are confidence intervals or point estimators preferred when making inferences?
Confidence intervals are preferred when making inferences
What is an unbiased estimator?
An unbiased estimator has an expected value equal to the population parameter
What is the most efficient estimator?
The most efficient estimator is the unbiased estimator with the smallest variance
What does a 95% CI mean?
That there is only a 5% chance that the population parameter is outside the range
What is the difference between a normal distribution and a student’s T Distribution?
A student’s T distribution normally has fatter tails
When do you use a T Table?
When there are few observations, typically fewer than 50, and when population variance is unknown
When do you use a z statistic vs. a t statistic?
You use a T statistic when the population variance is unknown, a z statistic when it is unknown
Can we make predictions even when we do not know the population variance?
Yes, but they will be less accurate
How are margin of error and confidence interval related?
When you have a smaller margin of error, you have a narrower confidence interval
How do higher sample sizes effect margin of error?
They decrease it
What is the margin of error in statistics?
A margin of error tells you how many percentage points your results will differ from the real population value
