Sample Mean and Standard Deviation After a Change. It is known that y = 11.6, sy = 4.4045, and n = 15. The observation y 12 = 7 is removed and observation 13 was misreported; it was not 10, but 20....

Sample Mean and Standard Deviation After a Change. It is known that y = 11.6, sy = 4.4045, and n = 15. The observation y¹²
= 7 is removed and observation
13 was misreported; it was not 10, but 20. Find ynew and s(new) after the changes.

Surveys on Different Scales. We are interested in determining whether UK voters (whose parties have somewhat more distinct policy positions than those in the USA) have a wider variation in their evaluations of the parties than voters in the USA. The problem is that the British election survey takes evaluations scored 0–10, while the US National Election Survey gets evaluations scored 0–100. Here are two surveys.

Using CV compare the amount of variation without worrying about the different scales.