Chapter 6 And 7 Flashcards
What is the key assumption in statistical inference
The sample is random
Point estimate
A measurement based on the sample that estimates the same measurement for the population
Ie the sample mean estimates the population mean
Confidence interval
The interval which measures possible values of the parameter (mean, median, mode) with a specific degree of confidence
If the degree of freedom increases the ______
Density curve becomes more normal
How is t-distribution similar to normal density
- symmetric (mean is 0) (bell shaped)
- single peaked
How is t-distribution similar to normal density
- t-density has bigger spread (longer tails)
- less probability in the centre and more probability in the tails
Margin of error
The difference b/w the sample and the population is the margin of error
Also the maximum likely difference b/w the pop and samp
If n of a sample increases the margin of error will _____
Decrease
If the confidence interval increases the margin of error ______
Increases
Statistical hypothesis
A guess about the population parameter
Type 1 error
The null hypothesis is accepted when it should be denied
Type 2 error
The null hypothesis is rejected when it should be accepted
Critical region
Region which should be rejected
Non-critical region
Region where the null hypothesis should be accepted
