On each trial of an experiment, a participant is presented with a constant soft noise, which is interrupted at some unpredictable time by a slightly louder sound. The time it takes for the participant to react to the louder sound is recorded. The following list contains the reaction times (in milliseconds) for 9 trials of this experiment:
558,781,786,585,585,558,558,585,740
a. What is the mean of this data set?
b. What is the medium of this data set?
c. How many modes does the data set have have? and what are there values