Question

1. True / False  
a.)   An Observational study is sufficient to claim causation. True or False?

b.)   The interquartile range is an accurate measurement of dispersion for skewed data sets. True or false?

c.)   Variance is a measure of central tendency. True or False?

d.)   One can find the mode of any data set. True or False?
      
e.)   The mean is an accurate measurement of central tendency for skewed data sets. True or false?

2. Outline how to perform simple random sampling given a list of your population.

Answer 1

Solution:

1)
a) An Observational study is sufficient to claim causation. False

The observational studies are not randomized, they cannot control for all of the other inevitable, often unmeasurable, exposures or factors that may actually be causing the results. Hence Observational study is not sufficient to claim causation.

b) The interquartile range is an accurate measurement of dispersion for skewed data sets. True.

The important advantage of interquartile range is that it is not affected by extreme values. The main disadvantage in using interquartile range as a measure of dispersion is that it is not amenable to mathematical manipulation.

c) Variance is a measure of central tendency. False.

Variance is the measure of variation in the data.

d) One can find the mode of any data set. False

The mode of a data set refers to the number that occurs most often. If there is not a number that occurs more than any other, we say there is no mode for the data. Hence One can not find the mode of any data set.

e) The mean is an accurate measurement of central tendency for skewed data sets. False.

The median an accurate measurement of central tendency for skewed data sets, because mean is effected by the extreme outliers.