Share
Explore BrainMass

Stats

Researchers conducted experiments with trees. Listed below are wights (kg) of trees given no fertilizer and trees treated with fertilizer and irrigation, Find the range, variance and standard deviation for each of the two samples, then compare the two sets of results. Does there appear to be a difference between the two standard deviations?

NO TREATMENT 0.16 0.35 0.18 0.16 0.04
FERTILIZE & IRRIGATED 2.15 0.26 1.95 0.35 2.32

a) Find the range for the trees that were given no treatment.
RANGE = ???Kg

b) Find the range for the trees treated with fertilizer and irrigation.
RANGE = ???Kg

c) find the variance and standard deviation for the trees that were given not treatment.

SAMPLE VARIANCE = ??? Kg2 (round to three decimal places)
SAMPLE STANDARD DEVIATION = ??? Kg (do not round until final answer then round to three decimal places)

d) Now find the variance and standard deviation for the trees treated with fertilizer and irrigation.

SAMPLE VARIANCE = ??? Kg2 (round to three decimal places)
SAMPLE STANDARD DEVIATION = ???Kg (do not round until final answer then rount to three decimal places)

e) Is there a difference between the 2 standard deviations? (choose correct answer)

1. No difference as both variances are very small.
2. Yes the treated trees have weight that vary less than weights of trees with
no treatment.
3. Yes the untreated trees have weights that vary less than treated trees.

Solution Summary

The solution provides step by step answer for each of the questions

$2.19