AP Statistics: Confidence Intervals Flashcards
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| 8726981200 | Point Estimate | a sample statistic that an unbiased estimate for a single number approximating the population parameter |  | 0 |
| 8726981201 | Unbiased Estimate | A statistic that is no more likely to overestimate than to underestimate the population parameter |  | 1 |
| 8726981202 | Margin of Error (general definition) | The maximum expected difference between a population parameter and a point estimate of a statistic obtained from a random sample |  | 2 |
| 8726981203 | Confidence Interval (CI) | A range of estimated values for a population parameter; the point estimate plus/minus the margin of error | 3 | |
| 8726981204 | Margin of Error for Population Mean | The critical value (t*) times the standard error of the sampling distribution of the sample mean |  | 4 |
| 8726981205 | Margin of Error for Population Proportion | The critical value (z*) times the standard error of the sampling distribution of the sample proportion |  | 5 |
| 8726981206 | Critical Value (Z* or T*) | The value of the test statistic that cuts off the most extreme values of a distribution; denoted with a * |  | 6 |
| 8726981207 | Confidence Level | The percentage of all possible samples of a given size that will generate a confidence interval that contains the true population parameter |  | 7 |
| 8726981208 | Increasing the sample size | If all other factors remain constant, the width of a confidence interval can be decreased by... |  | 8 |
| 8726981209 | Increase the confidence level | If all other factors remain constant, the width of a confidence interval must increase to... |  | 9 |
| 8726981210 | Standard error | An estimate of the standard deviation of a sampling distribution often used with confidence intervals since the population parameters are rarely known |  | 10 |
| 8726981211 | Standard error of the sample mean | Used when sigma is unknown and must be estimated by the sample standard deviation; requires the use of a t-distribution |  | 11 |
| 8726981212 | Standard error of the sample proportion | Used when the population proportion is unknown and must be estimated by the sample proportion; a z distribution is still used |  | 12 |
| 8726981215 | t-distribution | A family of unimodal, symmetric distributions with more variability (therefore higher tail probabilities) than a normal distribution; graphically a z-distribution with fat tails |  | 13 |
| 8726981216 | degrees of freedom | A statistic that describes the amount of variability in a distribution; larger values indicate smaller tail probabilities |  | 14 |