Question

Mercury is a persistent and dispersive environmental contaminant found in many ecosystems around the world. When released as an industrial by-product, it often finds its way into aquatic systems where it can have deleterious effects on various avian and aquatic species. The accompanying data on blood mercury concentration (µg/g) for adult females near contaminated rivers in a state was read from a graph in an article.

0.21	0.23	0.25	0.31	0.33	0.41	0.55	0.56
1.42	1.70	1.84	2.20	2.24	3.07	3.24

Determine the value of the 10% trimmed mean. (Round your answer to three decimal places.)

Answer 1

SOLUTION:

From given data,

0.21

0.23

0.25

0.31

0.33

0.41

0.55

0.56

1.42

1.70

1.84

2.20

2.24

3.07

3.24

Determine the value of the 10% trimmed mean. (Round your answer to three decimal places.)

Calculation for the 10% trimmed mean ,

Trimmed mean :

A 10% trimmed mean can be calculated by eliminating the smallest 10% and largest 10% of the sample than find the average for the remaining samples.

10% of the smallest value is 0.21 and the 10% of largest value is 3.24 , eliminate the two values and find the average for the remaining values as follows:

= (0.23+0.25+0.31+0.33+0.41+0.55+0.56+1.42+1.70+1.84+2.20+2.24+3.07) / 13

=15.11 / 13

= 1.162307

10% of the smallest value is 0.23 and the 10% of largest value is 3.07 , eliminate the two values and find the average for the remaining values as follows:

= (0.25+0.31+0.33+0.41+0.55+0.56+1.42+1.70+1.84+2.20+2.24) / 11

=11.81 / 11

= 1.073636

The trimmed mean is ,

= (+) / 2

= (1.162307+1.073636) / 2

= (2.235943​​​​​​​) / 2

= 1.118  (Round your answer to three decimal places)