Final answer:
The most suitable unit to measure reading speed is 'words per minute' because it indicates how many words are read in one minute, with minutes as the independent variable.
Step-by-step explanation:
The most appropriate unit to describe the rate at which one person reads is words per minute. This is because when discussing rates like reading speed, we are interested in how many words are read over a certain period of time. In this case, minutes are the independent variable, and words are the dependent variable. Therefore, we measure the quantity of words that are read each minute.
'Per' implies division, so we're dividing the number of words by the number of minutes. This similar concept is applied in other units of measure, such as velocity being expressed as meters per second.Words per minute is the most appropriate unit to describe the rate at which one person reads. The dependent quantity is the words, and the unit of measurement is expressed as the number of words per minute.