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.
The data logger flags any value outside the interval [0.07,0.43][0.07,0.43][0.07,0.43] g/km as a possible recording error.
Show that the mean is 0.25 g/km and the standard deviation is 0.09 g/km.
Determine which of the three stated values are flagged as possible recording errors.
The two largest values are found to be errors and are removed. Find the mean and the standard deviation of the remaining 28 values.