Question

The mean attendance of a class from Monday to Saturday was 34 if the main attendance on Monday Tuesday Wednesday and Thursday was 33 and that on Thursday Friday and Saturday was 35 then find the attendance on Thursday

Answer 1

Mean attendance of class from Mon. to Sat. , Mc = 34
Mean attendance of class for 1 day Mc = 37 × 6 =222
Mean attendance of class for Mon. to Thur. (Ma) = 33
Mean attendance of class for 1 day (Ma) = 33×4
= 132
Mean attendance of class from Thurs. to Sat. (Mb) = 35
Mean attendance of class for 1 day , (Mb) = 35 × 3 = 105
The attendance on Thursday is 2 × ( { (Ma) + (Mb) } - (Mc) )
= 2 × ( {132 + 105} - 222 )
= 2 × ( 237 - 222 ) = 2 × 15 = 30