PSYCH 100A Study Guide - Final Guide: Null Hypothesis, Confidence Interval, Sampling Distribution
Document Summary
Normal distributions: normal curves require large sample sizes for accurate results, 95% confidence intervals. Margin of error = 1. 96 x standard error. 95% of the values fall within 1. 96 standard deviation units (z-score) of the mean. T distribution: sample size-dependent sampling distribution. The critical value of 1. 96 varies according to sample size large sample size = lower critical value. Sample sizes near 100+ have a critical value near 1. 96. Very small sample sizes (i. e. ) have critical values >2. 2: 95% confidence interval. Confidence interval = estimate margin of error. Margin of error = critical value x standard error. It"s the correction factor that alters the shape of the normal curve to adjust for small samples. Helps determine critical value critical value will probably be given on test. Degrees of freedom for 1 sample = n 1. Degrees of freedom for 2 samples = n 2. Standard deviation of estimates across many samples.
