Suppose that a high school mathematics competition test score is a normal distribution, the average score is known to be 60 points, and the standard deviation is 10 points. If the results are scored in the fourth rank, the top 20% of the highest scores will be ranked as A, the next 20% will be ranked as B, the next 40% will be ranked as C, and the last 20% will be ranked as D.

Ask：
1, How many points or above can get the A rank？
2，How many points or below will get the D rank ？
3，If one of the students gets a B grade, how many points does the score fall between?
4，What is the 25th percentile？

Answer rating: 100% (QA)

ar A C solution ta Given Dota s mathemation test score ir normed d... View the full answer