in a class, every student received a grace score of 30 marks. How does this affe
ID: 3133790 • Letter: I
Question
in a class, every student received a grace score of 30 marks. How does this affect the average score? How does this affect the standard deviation of the scores?
I just choosed 5 random numbers without adding the 30 first (1,25,17,37,5) and once i added the 30 i got (31,55,47,67,35). I got an answer of 13.14534138 from the numbers that i did not add the 30 and for the other one i got 32.75362575. I don't remeber what numbers i plugged in or how i did it. Can someone please show me step by step. Thank you.
Explanation / Answer
WE HAVE TO COMPARE THE MEAN BEFORE ADDING 30 AND AFTER ADDING 30
LETS US TAKE THE RANDOM NUMBER CHOOSEN BY YOU.
BEFORE
(1,25,17,37,5)
MEAN = 85/5 = 17
THE STANDARD DEVIATION WILL BE =
NOW AFTER ADDING 30 TO EACH NUMBER
31,55,47,67,35
MEAN = 235/5 = 47
WHICH MEANS THAT THE MEAN IS INCREASED BY 30
STANDARD DEVIATION =
THE STANDARD DEVIATION IS SAME IN BOTH THE CASES.
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