Wearing a mask helps controlling seasonal influenza virus transmission. A guidance for the use of masks is available on the CDC (Centers for Disease Control and Prevention) website. Professor X has conducted a one-factor experiment using a completely randomized design to study how the duration of time that a specific medical mask remains effectively depends on the humidity levels. The calculations are summarized in an ANOVA of the one-way layout data he obtained. The results are recorded on a laboratory notebook. Recently, Professor X wanted to review the results of this experiment, but found his notebook has been partially damaged. On the data page, the data points for the first humidity level are blurred. Humidity level Duration (Quarter-hour)
1 blurred
2 34, 19, 16, 30, 22
3 23, 26, 31, 17
4 17, 13, 22
Professor X didn’t remember the number of replica for Level 1. Luckily, he found an ANOVA for this data set.
Df Sum Sq Mean Sq F value Pr(>F)
Group 3 518.64 172.88 4.547 0.0295
Residuals 10 380.22 38.02
Professor X needs your help. Please recover the original data and explain how you find them.