What is the optimal level of fluoride in water?

The agency's recommended ratio of fluoride to water, newly calibrated at 0.7 parts per million, results from years of scientifically rigorous analysis of the amount of fluoride people receive from all sources.

its first and third is your answer i did the qustion the fourth isnt right

here is table 2-2:

country

percent of eligible voters that voted

rank

united states

44.9%

138

canada

60.1%

107

costa rica

84.6%

14

hungary

66.9%

82

japan

57.0%

118

egypt

27.7%

159

south africa

85.5%

10

ans is no, the data set cannot be plotted as a single circle graph