BIOL 211D Lecture Notes - Lecture 2: Central Limit Theorem, Null Hypothesis, Bar Chart
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Sample is a smaller representation of the population. Reject or fail to reject the hypothesis. Null hypothesis: fertilizer has no effect on average plant height. Size of t tells us how different the means are weighted by how much uncertainty we have. Additive random variants will approximate a bell-shaped curve. Alpha level: 5% will be significant, 95% will not be. Lowering the alpha level increases the certainty. P-value quantifies how much area under the curve is to the left or right of the observed value. Compare t observed to the table of critical values. Total sample size, round down (more conservative) If t critical > t observed , p > alpha, fail to reject the null. A single value computed from your data. For the three tests you will use in this class, the test statistics are r (for correlation analysis), t (for a t-test), and (for a. Excel will calculate them or help you to calculate them.
