On each trial of an experiment, a subject is presented with a constant soft nois

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

20

trials of this experiment:

250, 226, 261, 231, 271, 257, 202, 296, 217, 269, 212, 193, 152, 236, 285, 273, 186, 171, 235, 229

Find

25

th and

80

th percentiles for these reaction times.

find the 25th percentile and 80th percentile

Explanation / Answer

Given trials of above experiments in ascending order as follows,

152,171,186,193,202,212,217,226,229,231,235,236,250,257,261,269,271,273,285,296

Here sample size (n) =20

To find 25th and 80th percentile.

25th percentile value is,

0.25*20 = 5th value from above sorted trials.

Thus, 5th value is 202

Therefore 25th percentile is 202.

Now,

80th percentile value is,

0.80 * 20 = 16th value from above sorted trails.

Thus, 16th value is 269

Therefore 80th percentile is 269.

Related Questions

Navigate

• Browse (All)
• Browse O
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.