Edexcel S1 2015 January — Question 7

Exam BoardEdexcel
ModuleS1 (Statistics 1)
Year2015
SessionJanuary
TopicNormal Distribution
TypeFind k given probability statement

  1. The birth weights, \(W\) grams, of a particular breed of kitten are assumed to be normally distributed with mean 99 g and standard deviation 3.6 g
    1. Find \(\mathrm { P } ( W > 92 )\)
    2. Find, to one decimal place, the value of \(k\) such that \(\mathrm { P } ( W < k ) = 3 \mathrm { P } ( W > k )\)
    3. Write down the name given to the value of \(k\).
    For a different breed of kitten, the birth weights are assumed to be normally distributed with mean 120 g Given that the 20th percentile for this breed of kitten is 116 g
  2. find the standard deviation of the birth weight of this breed of kitten.