Answer: Option 'b' is correct.
Step-by-step explanation:
Since we have given that
Number of people showed in a recent poll = 1800
Percentage of people believe gas prices will go down = 35%
So, best point estimate of the proportion of all people who believe gas prices will go down is given by
[tex]\frac{35}{100}\\\\=0.35[/tex]
and Number of people who believe gas prices will go down is given by
[tex]0.35\times 1800\\\\=630[/tex]
Hence, Option 'b' is correct.