A federation of play-based nursery and elementary schools has found, in the children at its schools, a correlation of 0.65 between time spent playing with brick-based construction toys in nursery school (in minutes per day) and first grade math score (on a scale of 0 to 100). Which of the following is implied by this information? a. Playing with brick-based construction toys in nursery school causes an increase in first grade math score.
b. If the time spent playing with brick-based construction toys had been recorded in hours per day instead of minutes per day, then the correlation would have been 0.65/60.
c. When time spent playing with brick-based construction toys (in minutes per day) increases by 1, the average increase in first grade math score is 0.65.
d. If two children are selected from those included in the study, then the one with the greater time spent playing with brick-based construction toys will have the higher first grade math score.
e. Less than half of the variation in first grade math score can be explained by the regression line of first grade math score on time spent playing with brick-based construction toys in nursery school.