Question

On each trial of an experiment, a subject is presented with a constant soft noise, which is interrupted at some unpredictable time by a noticeably louder sound. The time it takes for the subject to react to this louder sound is recorded. The following list contains the reaction times (in milliseconds) for the trials of this experiment: 296, 311, 202, 217, 231, 171, 241, 164, 257, 269, 175, 273, 285, 226, 261 Find 25th and 80th percentiles for these reaction times.

Answer 1

Answer:

25th percentile = 202

80th percentile = 285

Step-by-step explanation:

Rearranging the values in increasing order

164

171

175

202

217

226

231

241

257

261

269

273

285

296

311

N = total number of variables = 15.

25th percentile = [(N + 1)/4]th variable = (15 + 1)/4 = 4th variable.

So, the 25th percentile = 4th variable = 202.

80th percentile = 0.8(N + 1) th variable = 0.8 × (15 + 1) = 12.8th variable = 13th variable = 285