Q3) A 2020 survey of adult bicycle travelers revealed the following age structure: Age group Proportion 18 to under 45 years 30 % 45 to under 65 years 30 % 65 to 80 years 40 % a) What is the average...

Q3) A 2020 survey of adult bicycle travelers revealed the following age structure:
Age group Proportion
18 to under 45 years 30 %
45 to under 65 years 30 %
65 to 80 years 40 %

a) What is the average age of bicycle travelers?
b) What age is exceeded by 25 % of all bicycle travelers?
c) What is the percentage of bicycle travelers under 30 years of age?
d) Describe in words how the histogram is drawn for this data set. What does "the principle of area fidelity" mean in this context?