Multiple choice: Select the best answer for Exercises 75 to 78. You have an SRS of 23 observations from a large population. The distribution of sample values is roughly symmetric with no outliers. What critical value would you use to obtain a 98% confidence interval for the mean of the population? (a) 2.177 (b) 2.183 (c) 2.326 (d) 2.500 (e) 2.508

Week 3: Distribution of Data (rest of Ch.2) 20 September, 2016 Basic Statistics for Research Professor HK Dong Wendy Liu Summary of Standard Notation: Variable sample Population Mean Standard deviation Variance Data set size 5 number summary – forms box & whisker plot Min – smallest value in data set th Q1– 25 percentile; 25% of data is below it o aka the median of min-Q 2 Q – aka the median – splits data in half 2 equally at 50% mark Q3– 75 percentile; 75% of data is below it o aka the median of Q2-max Max – largest value in data set Outlier data – marked as an asterisk (*) on box&whisker plot Q + 1.5IQR = upper limit: da