The accompanying summary data on CeO2 particle sizes (nm) under certain experimental conditions was read from a graph in an article.
3.0–<3.5 3.5–<4.0 4.0–<4.5 4.5–<5.0 5.0–<5.5
6 15 26 33 21
5.5–<6.0 6.0–<6.5 6.5–<7.0 7.0–<7.5 7.5–<8.0
14 6 3 5 2
(a)
What proportion of the observations are less than 5? (Round your answer to three decimal places.)
(b)
What proportion of the observations are at least 6? (Round your answer to three decimal places.)