Final answer:
The Sun is higher in the sky later in the morning.
Step-by-step explanation:
The best explanation for Samantha's results is that the Sun is higher in the sky later in the morning.
This can be observed by the length of time the Sun spends above the horizon. During summer, the Sun's path is longest, resulting in longer days. In contrast, during winter, the Sun's path is shortest, resulting in shorter days.
Additionally, in summer, the Sun appears high in the sky and its rays hit Earth more directly, spreading out less. In winter, the Sun is low in the sky and its rays spread out over a wider area, becoming less effective at heating the ground.