JEE Main 201910 Apr, Morning shiftMathematicsHardStatistics and Probability258× since 2002
If for some x R, the frequency distribution of the marks obtained by 20 students in a test is :
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Marks
2
3
5
7
Frequency
(x + 1)²
2x - 5
x² - 3x
x
then the mean of the marks is