Answer:
3.5 mm
Explanation:
Given the size of the sun, the scale ratio is :
[tex]\dfrac{1m}{1,392,000km}[/tex]
Now to determine how large the smallest planet should be, you just need to make sure that its measurement is proportion to that scale. According to your table, the smallest planet is Mercury with a diameter of 4,879.4 km. Now we can write a proportion for this, to determine the scale:
[tex]\dfrac{1m}{1,392,000km}=\dfrac{x}{4,879.4km}[/tex]
Cross multiply then divide to solve for x.
[tex]\dfrac{1m\times 4,879.4}{1,392,000km}=x\\\\\dfrac{4,879.4m}{1,392,000}=x\\\\0.00350m=x[/tex]
So the smallest planet would be 0.0035m. Since your choices are in mm (and that is a very small number to estimate) we can convert it into mm.
1 meter = 1,000 millimeters
[tex]0.0035m\times\dfrac{1,000mm}{1m}=3.5mm[/tex]
The answer is then 3.5mm.
