Question

On each trial of an experiment, a participant is presented with a constant soft noise, which is interrupted at some unpredictable time by a slightly louder sound. The time it takes for the participant to react to the louder sound is recorded. The following list contains the reaction times (in milliseconds) for 8 trials of this experiment:

486, 358, 395, 759,496, 692, 353, 306 0
(a) What is the mean of this data set? If your answer is not an integer, round your answer to one decimal place.
(b) What is the median of this data set? If your answer is not an integer, round your answer to one decimal place.
(c) How many modes does the data set have, and what are their values?

Answer 1

480.6 ; 440.5, 8 mode values

Explanation:

Given that :

Given the data :

486, 358, 395, 759,496, 692, 353, 306

Rearranged data: 306, 353, 358, 395, 486, 496, 692, 759

The mean:

Σx/ n

n = sample size = 8

Σx = sum of all data values = 3845

Mean = 3845 / 8

Mean = 480.6

The median :

0.5(n + 1)th term

0.5(8 + 1) th term

0.5(9)th term

= 4.5term

(4th + 5th term) / 2

(395 + 486) / 2

= 440.5

The mode = most frequently occurring data value ; since all the data values have a frequency of 1, then the number of modes = 8.