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Dispersion and Spread of Data

Testing a claim given a confidence level, mean and standard deviation.

Sample data was collected in a study of calcium supplements and their effects on blood pressure. A placebo group and a calcium group began the study with blood pressure measurement. At a 0.05 significance level, test the claim that the 2 sample groups come from populations with the same mean. Placebo mean: 114.6538, standard d


The time taken to install bumpers on cars passing through a particular assembly line is normally distributed with mean time u=2.00 minutes and standard deviation =36 minutes. A sample on n=100 is obtained and a mean bumper installation time X-bar will be calculated. 1. Find the value of standard deviation X bar. Determine th

Statistics Problem

1. Bill has completed a ten question multiple choice test on which he answered seven questions correctly. Each question had one correct answer to be chosen from four alternatives. Bill says that he answered the test by randomly selecting the answers without reading the questions or answers. a. What is the expected number of