The table shown shows the heights of voices.
To get the tallest height you calculate the mean of each voice.
Mean height of soprano;
(60+62+62+64+65+65+66+66+67+68)/10 = 645/10 =64.5
Mean height of alto;
(60+61+62+63+64+65+66+69+70+72)/10 =592/10 =59.2
Mean height of tenor;
(64+66+66+67+68+70+72+73+74+76)/10 = 550/10 =55
mean height of Bass;
(66+68+68+69+70+70+71+72+73+75)/10 = 702/10 =70.2
The two voice parts that have the tallest singers are Soprano and Bass.
These is because the two voices have the highest average height.