Question

The reacttimes data set has 50 observations of human reaction times to a physical stimulus. The reaction times are named Times and arranged in increasing order below. 0.12 0.30 0.35 0.37 0.44 0.57 0.61 0.62 0.71 0.80 0.88 1.02 1.08 1.12 1.13 1.17 1.21 1.23 1.35 1.41 1.42 1.42 1.46 1.50 1.52 1.54 1.60 1.61 1.68 1.72 1.86 1.90 1.91 2.07 2.09 2.16 2.17 2.20 2.29 2.32 2.39 2.47 2.60 2.86 3.43 3.43 3.77 3.97 4.54 4.73

4. Find the 60th percentile of Times using R’s quantile( ) function.

5. Find the 40th percentiles of mydata and mydata[-21] by hand and also by using R.

8. The 40th value T imes(40) of the reaction time data is 2.32. Change it to 232.0 and recalculate the mean and median. You can make the change in R by > Times[40]=232.0 Change it back after you are finished with this exercise.

Answer 1