Singers in the New York Choral Society

Step 1: Graph Graph > Boxplot > with Groups, Graph variable=Height, Categorical variable=Voice

Step 2: Summary Statistics
Stat > Basic Statistics > Display Descriptive Statistics, Variable= Height, By variables=Voice

Group Sample Size Mean Std

Soprano 36 64.250 1.873

Alto 35 64.886 2.795

Tenor 20 69.150 3.216

Bass 39 70.718 2.361

Group	Sample Size	Mean	Std
Soprano	36	64.250	1.873
Alto	35	64.886	2.795
Tenor	20	69.150	3.216
Bass	39	70.718	2.361

Step 3: Hypothesis Test Stat > ANOVA > Oneway, Response=Height, Factor=Voice, Graphs > Residual vs. Fits Plot and Normal Plot

everything fine

1) α=0.05
2) H₀: α₁ = .. =α₄=0 (no difference in the mean heights for different voices)
3) H_a: α_i≠0 for some i (some differences in the mean heights for different voices) 4) p-value= 0.000 < α
5) We reject H₀, there are some differences in the mean heights for different voices

Step 4: Multiple Comparison
Stat > ANOVA > Oneway, Response=Height, Factor= Voices , Comparisons > Check Tukey

Soprano Alto Tenor Bass

___________________

___________________

There is a stat. significant difference in the heights of Sopranos and Altos on one hand, Tenor and Bass on the other. Note: Sopranos and Altos are female voices whereas tenor and Bass are male voices.

Soprano	Alto	Tenor	Bass
___________________
		___________________