Is the following data discrete or continuous? Here are the finishing times taken for a race in seconds.
$$10.1,10.6,11.2,12.1,10.9,11.3$$
Is this data discrete or continuous?
My understanding is that time is continuous data but these data are presented in a to-one-decimal-place form. 
Are they now discrete?
 A: The concept of 'continuous data' is a theoretical convenience. In practice,
all data must be rounded to a certain number of decimal places.
Theoretically, running times are continuous. One can imagine infinitely
many values between 10.1 and 10.2, even if the measurement device is
not up to measuring them. Maybe the winner between 10.1 and 10.2 would
be determined by a photograph.
Whether you model these six observations as continuous or discrete may be
a matter of tradition or convenience. 
How will you plot the data? Perhaps
a dotplot or stripchart, focusing attention on the six individual discrete values
observed.

Or perhaps you might use a histogram, speculating on the theoretical continuous
distribution that may have produced these data. Six observations are
not nearly enough for this to be successful, but below we show the "best-fitting" normal density (blue curve) and a kernel density estimator (green), just to
give an idea of what might be done with more observations. The tick
marks beneath the histogram show the six observations.

