Question

Students in an experimental psychology class did research on depression as a sign of stress. A test was administered to a sample of 30 students.The scores are shown below.

43 51 11 90 76 36 64 37 42 72 54 62 36 74 51 72 37 29 39 61 48 63 36 41 21 37 51 46 86 13

To find the​ 10% trimmed mean of a data​ set, order the​ data, delete the lowest​ 10% of the entries and the highest​ 10% of the​ entries, and find the mean of the remaining entries. Complete parts​ (a) through​ (c). ​(a) Find the​ 10% trimmed mean for the data. The​ 10% trimmed mean is nothing. ​(Round to the nearest tenth as​ needed.)

Answer 1

The given 30 student scores are first inserted in ascending order here as:

11, 13, 21, 29, 36, 36, 36, 37, 37, 37, 39, 41, 42, 43, 46, 48, 51, 51, 51, 54, 61, 62, 63, 64, 72, 72, 74, 76, 86, 90

Now as there are a total of 30 students, trimmed 10% mean is mean of number after removing the first 3 numbers and the last 3 numbers to get here:

29, 36, 36, 36, 37, 37, 37, 39, 41, 42, 43, 46, 48, 51, 51, 51, 54, 61, 62, 63, 64, 72, 72, 74

Then the mean here is computed as:

Therefore 49.25 is the required trimmed mean here.