Skip to content

Course home

2.2.3 Central tendency, variation and standard deviation

2.2.3 Central tendency, variation and standard deviation

EasyMediumHard
1234567891011
Question 1

The CO emission x x\,x g/km of each of 30 cars is recorded. For these cars,

∑x=7.5\sum x = 7.5∑x=7.5 and ∑x2=2.118\sum x^2 = 2.118∑x2=2.118

The two largest recorded values are 0.48 g/km and 0.55 g/km, and the smallest is 0.08 g/km.

For this question, a value is defined to be an outlier if it is more than two standard deviations from the mean.

a.

Show that the mean is 0.25 g/km and the standard deviation is 0.09 g/km.

[2]
b.

Determine which of the recorded values are classed as outliers.

[2]
c.

The two largest values are found to be errors and are removed. Find the mean and the standard deviation of the remaining 28 values.

[3]
Markscheme

2.2.3 Central tendency, variation and standard deviation Questions

  1. A Level
  2. /Maths
  3. /2.2.3 Central tendency, variation and standard deviation

39 exam-style questions on AQA A Level Maths 2.2.3 Central tendency, variation and standard deviation. Each one has a worked solution and a mark scheme showing where the marks go.

Question bank