The percentiles, quartiles, and deciles for a continuous random variable can be approximated from a relative cumulative frequency ogive using the projective method. For instance, in we approximated the 50th percentile for A, the life span of a lithium battery, to be 850 hours.
(a) Approximate the first quartile for A, the cadmium level in the air, using the data of
(b) Approximate the fourth decile for A, the number of gallons of liquid product obtained per ton of coal fuel, using the data.
(c) Approximate the 50th percentile for X, the percentage ash content for a particular variety of moss using the data.