Exam Module 3 | Assignment

Exam Module 3
1. Find the mean and median for the following three variables:
A B C
8 4 6
5 4 2
7 6 3
1 3 4
3 4 1
Variable A: Mean = 8+5+7+1+3
5 =4.8 ; Median:5
Variable B: Mean = 4+ 4+ 6+3+ 4
5 =4.2; Median :4
Variable C: Mean = 6+2+3+ 4+1
5 =3.2 ; Median:3
2. You recorded the time in seconds it took for 8 participants to solve a puzzle. These
times appear below. However, when the data was entered into the statistical
program, the score that was supposed to be 22.1 was entered as 21.2. You had
calculated the following measures of central tendency: the mean, the median, and
the mean trimmed 25%. Which of these measures of central tendency will change
when you correct the recording error?
15.2
18.8
19.3
19.7
20.2
21.8
22.1
29.4
Since the mean and the trimmed mean are averages and include the
incorrect data, they will be affected by the error hence they will
change. For the trimmed mean, 29.4 and 21.8 would be trimmed
leaving the incorrect 21.2 in the data. The median in this case will
not change because it is independent of the botched data.
3. For the test scores in question #2, which measures of variability (range, standard
deviation, variance) would be changed if the 22.1 data point had been erroneously
recorded as 21.2?
The standard deviation and variance would change.