Final answer:
The correct number of degrees of freedom for paired measurements of 47 children's heights, measured twice at age 5 and 6, is 46.
Step-by-step explanation:
The correct number of degrees of freedom in this scenario is calculated based on the number of paired measurements.
As 47 children's heights are measured at age 5 and again at age 6, these are considered paired measurements. Since there are 47 children, we start with 47 pairs of measurements.
For each pair, we lose one degree of freedom when we calculate the mean of the differences for the paired samples.
Therefore, the correct number of degrees of freedom for this dataset would be 47 (total number of observations) - 1 (number of constraints) = 46 (degrees of freedom) which is 46.