Given ,
Neptune's average distance from the sun is
![4.503*10^9\text{ km}](https://img.qammunity.org/2023/formulas/mathematics/college/h7mvaw7cugp0xi4gf2qlu62qu3vpe6hgox.png)
Mercury's average distance from the sun is,
![5.791*10^7\text{ km}](https://img.qammunity.org/2023/formulas/mathematics/college/jd5oga4rregusjflnjryycpg6e5chjm1oz.png)
Hence to find out the value by which Neptune is farther from the Sun than the Mercury, we can take take the ratio of the two values. That is,
![(4.503*10^9)/(5.791*10^7)=0.7776*10^(9-7)=77.76](https://img.qammunity.org/2023/formulas/mathematics/college/e8vi2ip2b26o21uej5vvqpcxulvn82cffk.png)
Thus, the Neptune is 77.76 times farther than the Mercury.