Each singer in the New York Choral Society in 1979 self-reported his or her height to the nearest inch. Their voice parts in order from highest pitch to lowest pitch are Soprano, Alto, Tenor, and Bass. The first two are typically sung by female voices and the last two by male voices. The data can be found in the data file SingerHeights.
a. Produce comparative boxplots of the distributions of heights by singing part. Comment on similarities and differences in the distributions of heights across the four parts. Use these boxplots to answer:
• Which part has the highest median height? What is the value of that median?
• Which part has the tallest singer? How tall is that singer?
• Which part has the smallest interquartile range of heights? What is the value of that IQR?
• Which part has the smallest lower quartile of heights? What is the value of that lower quartile?
b. Calculate the sample size, sample mean, and sample standard deviation of the heights within each group (singing part). Use these statistics to answer:
• Which part has the most singers? What is the value of that sample size?
• Which part has the largest sample mean height? What is the value of that mean?
• Which part has the largest standard deviation of heights? What is the value of that standard deviation?
c. Treat these data as a random sample of all singers. Conduct an ANOVA analysis to test whether the sample data provide evidence that the mean heights diff er significantly among the four parts. Report the ANOVA table, hypotheses, test statistic, and p-value. Also summarize your conclusion.
d. Check and comment on whether the validity conditions for ANOVA appear to be satisfied here.

e. Produce confidence intervals to determine which parts’ mean heights differ significantly from which others. Summarize your findings.