Edexcel S1 2017 June — Question 1

Exam BoardEdexcel
ModuleS1 (Statistics 1)
Year2017
SessionJune
TopicMeasures of Location and Spread
TypeCalculate statistics from grouped frequency table

  1. Nina weighed a random sample of 50 carrots from her shop and recorded the weight, in grams to the nearest gram, for each carrot. The results are summarised below.
Weight of carrotFrequency (f)Weight midpoint \(( \boldsymbol { x }\) grams \()\)
\(45 - 54\)549.5
\(55 - 59\)1057
\(60 - 64\)2262
\(65 - 74\)1369.5
$$\text { (You may use } \sum \mathrm { f } x ^ { 2 } = 192102.5 \text { ) }$$
  1. Use linear interpolation to estimate the median weight of these carrots.
  2. Find an estimate for the mean weight of these carrots.
  3. Find an estimate for the standard deviation of the weights of these carrots. A carrot is selected at random from Nina's shop.
  4. Estimate the probability that the weight of this carrot is more than 70 grams.