The following figure is a fan-shaped statistical chart of the number of sixth-grade students participating in extracurricular interest groups. Calligraphy: 8 artists: 30% singing: 40% technology: 25%.

Eight students in the sixth grade (1-30%-40%-25%) =160.

Calligraphy group 8 people

Art group 160x30%=48 people.

Singing group 160x40%=64 people.

Science and technology group 160x25%=40 people.