Researchers were studying how playing a dancing video game impacts heart rate. They measured the heart rates (in beats per minute) of 15 subjects before they danced a song and again after they finished dancing the song. They want to use these results to estimate the average difference between before and after heart rates.
What type of statical test used in this case?
A. A t-test for a mean
B. A z-test for a proportion
C. A paired t-interval for the mean difference
D. A z-interval for a proportion
E. A t-interval for a mean
