These data come from an experiment that investigated the effects of content of stimuli (presented in photo form) and length of presentation of stimuli on people's anxiety as measured by heart rate.Participants were randomly assigned to view one photo under one of the three durations.

Photo/ Photo A Photo B Photo C Photo D Duration Short 60, 65, 65, 60, 73, 80, 75, 82, 70 72 85 88 Medium 62,58, 70, 75, 76, 86, 78, 89, 67 78 90 93 Long 57,62, 71, 75, 68, 63, 70, 65, 70 79 72 75