A student claims that 50% of a sample of data is less than the median and 50% of data is greater than the median, therefore the data is symmetric. What is the student's error?

a) The student did not make an error

b) It is impossible for 50% of the data values to be both less than and greater than the median, so you can't determine whether or not the data is symmetric.

c) While 50% of the data values are always greater than the median, the data may have greater variability on one side of the median than the other.

d) Data is never symmetric, so this assumption is incorrect.