Final answer:
The null hypothesis for the test on toddlers' color preferences posits that there is no difference in the distribution of color preferences between male and female toddlers for the first toy chosen.
Step-by-step explanation:
The appropriate null hypothesis for this test concerning whether male and female toddlers show a preference for certain colors is that there is no difference in color preference between male and female toddlers. When conducting a hypothesis test in statistics, the null hypothesis often posits no effect or no difference between groups.
In this context, for the toys of different colors chosen by toddlers, the null hypothesis (H0) would be: 'There is no difference in the distribution of color preferences between male and female toddlers for the first toy chosen.'
This statement sets the expectation that male and female toddlers would, on average, choose toys of each color at similar rates.