Please see question below:

In an experiment to study the relationship between age X and vocabulary size Y for young children, 4 children of particular ages were selected and vocabulary size was determined for each child. Age 2 3 4 5 Vocab 200 1000 1500 2100 a) Estimate the average vocabulary size for 4 year old children. bj happens if you use the estimated regression equation to predict vocabulary size for a one year old child ? Explain this phenomenon if an explanation is necessary