Visualizing the distribution of gestational length. The gestation length illustrative example presented earlier in this chapter established that uncomplicated pregnancies vary according to a Normal distribution with μ = 39 weeks and σ = 2 weeks. Sketch a Normal curve depicting this distribution. Label its horizontal axis with landmarks that are ±σ and ±2σ on either side of the mean.

Remember to use the curve’s inflection points to establish distances for landmarks.