The CO emissions of 24 cars have mean 0.25 g/km and standard deviation 0.06 g/km.
A 25th car, with a CO emission of 0.49 g/km, is added to the sample.
Find the mean CO emission of the 25 cars.
Find the standard deviation of the CO emissions of the 25 cars.
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.