A developmental psychologist was interested in how long babies take to complete a hand-eye coordination task (put a ball in a hole) and whether this skill improves during the course of early development. They recruited a total of seven 12-month olds, seven 16-month olds, seven 20-month olds, and seven 24-month olds. Below is the data.

Age	12 months	16 months	20 months	24 months
Mean time (seconds)	37	22	18	14
SD	23	24	12	19

The grand mean is ________ . The between condition variance is ________. The within condition variance is ______ . This gives an F ratio of ____________ .

What is the critical value for the previous question and your conclusion?