Carcass wrote:
my solving
but what I thought is that if there are 100 people, and score is distributed normally(1 to 100)
John's score is 32. so less than 32 is 31(31 people)
Jane's score is 68. so equal to or greater than 68 is 32(32 people with Jane)
than Quantity can be greater, but what's the problem of my solving?
this is answer from book.
Percentiles define the proportion of a group that scores below a particular benchmark. Since John scored in the 32nd percentile, by definition, 32% of the class scored worse than John. Quantity A is equal to 32%
Jane scored in the 68th percentile, so 68% of the class scored worse than she did. Since 100 - 68 = 32, 32% of the class scored equal to or greater than Jane. Quantity B is also equal to 32%
official answer is C (so Quantity A is equal to Quantity B)
Help on this
Plz if someone can guide me on this
:
My reasoning,
Since it is a normally distributed curve, and if I consider with the total of 100 students,
so the number of students from 32 to 68 = 50 i.e if 50 is taken as mean then 18 will be 1 SD below = 32 and 18 will 1 SD above mean = 68
i.e. 68% consist of the students whose score is in between John and jane
and the rest 32% will consist the score that are either below or above the score of John and Jane. i.e. half of 32% i.e. 16% will be below John's score and the other 1/2 i.e. 16% will be above Jane's score.
Hence the two quantities will be equal