Fifty students report their nightly sleep. The cumulative relative frequency reaches 0.28 at six hours and the next reported value is seven hours. What is the 28th percentile?

1. Twenty-eight percent of 50 values is 14 values, so 14 students sleep less than the 28th percentile. 2. Those 14 students are exactly the ones reporting four, five and six hours. 3. The percentile therefore falls between the last six and the first seven, which puts it at 6.5 hours. 4. Reading it as 6.0 hours would place it on an observed value rather than between the two groups. _Source: OpenStax Introductory Business Statistics (CC BY 4.0), Ch 2 "Descriptive Statistics", section 2.2 Measures of the Location of the Data_