Chapter 1: Q12E (page 25)
The accompanying summary data on CeO2 particlesizes (nm) under certain experimental conditions wasread from a graph in the article 鈥淣anoceria鈥擡nergetics of Surfaces, Interfaces and WaterAdsorption鈥 (J. of the Amer. Ceramic Soc., 2011:3992鈥3999):
3.0鈭&濒迟;3.5 3.5鈭&濒迟;4.0 4.0鈭&濒迟;4.5 4.5鈭&濒迟;5.0 5.0鈭&濒迟;5.5
5 15 27 34 22
5.5鈭&濒迟;6.0 6.0鈭&濒迟;6.5 6.5鈭&濒迟;7.0 7.0鈭&濒迟;7.5 7.5鈭&濒迟;8.0
14 7 2 4 1
a. What proportion of the observations are less than 5?
b. What proportion of the observations are at least 6?
c. Construct a histogram with relative frequency on the vertical axis and comment on interesting features. In particular, does the distribution of particle sizes appear to be reasonably symmetric or somewhat skewed? (Note:The investigators fit lognormaldistribution to the data; this is discussed in Chapter 4.)
d. Construct a histogram with density on the vertical axis and compare to the histogram in (c).
Short Answer
a. The proportion of observations that are less than 5 is 0.618.
b. The proportion of observations that are at least 6 is 0.107
c. The histogram is represented as,

The shape of the distribution is not symmetric.
d. The histogram is represented as,



