Statistics for DM(Unit 1 & 2)

The average of the deviations of the observations from their mean is always zero.

• True

• False

Answer explanation

The statement is true because the sum of deviations from the mean is always zero, resulting in an average of zero.

The standard deviation is a measure of how much the data points deviate from the mean

• True

• False

Answer explanation

The statement is true because the standard deviation measures the dispersion of data points around the mean.

The variance is calculated as the average of the squared deviations from the mean.

• True

• False

Answer explanation

The statement correctly describes how variance is calculated, making the answer True.

Kurtosis measures the degree of flatness or peakedness of a data distribution.

• True

• False

Answer explanation

Kurtosis measures the degree of tailedness, not flatness or peakedness, making the correct answer False.

A correlation coefficient of +0.75 indicates a stronger positive relationship between two variables than a correlation coefficient of +0.30

• True

• False

Answer explanation

A correlation coefficient of +0.75 indicates a stronger positive relationship between two variables than a correlation coefficient of +0.30, making the statement true.

Correlation implies causation, meaning that if two variables are correlated, one variable causes the other to change

• True

• False

Answer explanation

Correlation does not imply causation. Just because two variables are correlated does not mean that one variable causes the other to change.

When the dataset contains extreme values or outliers, the (a)   might be a more appropriate measure of central tendency than the mean.

(a)   kurtosis indicates a sharper, more peaked distribution, while Negative kurtosis indicates a flatter distribution.

In a perfectly symmetrical distribution, the skewness is ___ and the kurtosis is ___

• 0,3

• 3,0

• 1,3

• 3,1

Answer explanation

In a perfectly symmetrical distribution, the skewness is 0 and the kurtosis is 3. Therefore, the correct answer is 0,3.

The (a)   is a measure of relative variation and is calculated as the standard deviation divided by the mean, expressed as a percentage.