Edexcel S1 2010 January — Question 7

Exam BoardEdexcel
ModuleS1 (Statistics 1)
Year2010
SessionJanuary
TopicNormal Distribution
TypeStandard two probabilities given

  1. The heights of a population of women are normally distributed with mean \(\mu \mathrm { cm }\) and standard deviation \(\sigma \mathrm { cm }\). It is known that \(30 \%\) of the women are taller than 172 cm and \(5 \%\) are shorter than 154 cm .
    1. Sketch a diagram to show the distribution of heights represented by this information.
    2. Show that \(\mu = 154 + 1.6449 \sigma\).
    3. Obtain a second equation and hence find the value of \(\mu\) and the value of \(\sigma\).
    A woman is chosen at random from the population.
  2. Find the probability that she is taller than 160 cm .