STAT 101 Lecture Notes - Lecture 17: Confidence Interval, Sample Size Determination, Sampling Distribution
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Stat 101 - introduction to business statistics - lecture 17: confidence interval for. The reason why the t is different from a z is that the s in the denominator will vary from sample to sample, whereas the in the z is just a fixed number. The degrees of freedom is necessary because there will be more variability in s for small sample sizes than for large sample sizes. In fact, as n becomes large, tn 1 turns into a z. We have an independent sample from the population. Sample size is large enough to use clt. Approximate 95% ci for the population proportion: Ex) a pharmaceutical company needs to compare the performance of its clinical trials to an industry benchmark. One way of measuring this is to look at the proportion of trials that move from phase i to phase ii. The attrition rate measures the proportion of trials that fail to make it to phase ii.
