OCR MEI S1 2007 June — Question 3

Exam BoardOCR MEI
ModuleS1 (Statistics 1)
Year2007
SessionJune
TopicMeasures of Location and Spread
TypeIdentify outliers using mean and standard deviation

3 The marks \(x\) scored by a sample of 56 students in an examination are summarised by $$n = 56 , \quad \Sigma x = 3026 , \quad \Sigma x ^ { 2 } = 178890 .$$
  1. Calculate the mean and standard deviation of the marks.
  2. The highest mark scored by any of the 56 students in the examination was 93 . Show that this result may be considered to be an outlier.
  3. The formula \(y = 1.2 x - 10\) is used to scale the marks. Find the mean and standard deviation of the scaled marks.