Six observations have mean 10. Five of the observations are 4,7,9,12,134,7,9,12,134,7,9,12,13.
a.
Find the sixth observation.
[2]
b.
Calculate the sample standard deviation of all six observations.
[2]
Markscheme
2.2.12 Variance and standard deviation Questions
8 exam-style questions on OCR (MEI) A Level Maths 2.2.12 Variance and standard deviation. Each one has a worked solution and a mark scheme showing where the marks go.