A histogram of gestational age at birth.

The horizontal axis is labeled Gestational age (weeks) and numbered 20, 25, 30, 35, 40, 45, with ticks at every integer. The vertical axis is labeled Frequency and numbered 0, 100, 200, 300, 400, 500.

There are vertical bars with bases 20.5 to 21.5, 21.5 to 22.5, 22.5 to 23.5, 23.5 to 24.5, and so on, and with heights 1, 1, 2, 1, 1, 4, 7, 1, 4, 7, 11, 11, 11, 35, 49, 135, 256, 400, 459, 285, 55, 11, 2.

The mean minus two standard deviations is shown at gestation = 34.4. The mean minus one standard deviation is shown at gestation = 36.7. The mean is shown at gestation = 39.0. The mean plus one standard deviation is shown at gestation = 41.2. The mean plus two standard deviations is shown at gestation = 43.5.

Back to Clinical Biostatistics: Data, frequencies, and distributions.

This page maintained by Martin Bland.

Last updated: 2 August, 2006.