For a sample of values, the mean of x x\,x is 12 and the sample standard deviation is 3. A new variable is defined by y=2x−5y=2x-5y=2x−5.
Find the mean of yyy.
Find the sample standard deviation of yyy, explaining why subtracting 5 has no effect on it.
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.