True or false ( Explain why .): A school administrator is running a regression of fall quarter final grades (Y ) on undergraduate grades (X). Since he only has data on graduate students, he does not...

True or false (Explain why.): A school administrator is running a regression of fall quarter final grades (Y ) on undergraduate grades (X). Since he only has data on graduate students, he does not have people who performed poorly in their undergraduate studies. His sample is therefore nonrandom (selection on X) and her estimates will be biased.