True or False for the three statements If an exremely large

True or False for the three statements:

If an exremely large observation (an outlier) is added to the data set, the mean will be larger than the median?

If the distribution of values is symmetric, then the mean median, and mode should all be roughly the same?

Surveys do not ned random assignment, bu comparative studies do imply random assignment?

I said true, true, false. I am not quite sure about the last statement? help

Solution

1) true (mean would become larger than median because mean depends on magnitude of values while median is positional average and depends on size of sample.

2) True

3) False. (Before conducting the survey at large scales sometimes we need to perform the random assignments for various purposes, such type of random assignments are called pivot surveys)