Question

2. The truth will prevail. (Justify your answers, no justification, no credit). (12 points each) a) In any given sample, the median is never larger than the mean, unless the distribution is symmetric. True or False. b) The sign of the correlation coefficient provides us with information regarding how good a line fits the data points we are studying. True or False. c) The range is always larger than the inter-quartile range. True or False

Answer 1

False ;

False ;

False

Explanation:

In a perfectly symmetric distribution, the mean and Median values are the same. But for skewed distributon, the median is greater than the mean (negatively skewed or left skewed data). Hence, the assertion is false.

The sign of the correlation Coefficient does not give information about how good a line fits. The sign attached to the correlation Coefficient gives information about the slope and hence, the type of relationship between the variables.

Positive (+) sign = positive relationship between variables ; negative (-) sign = negative relationship between variables.

C.)

The value of the range is not always higher Than the value of the interquartile range. The IQR might have the same value as the value of the range.

For instance :

Given the data :

1, 1, 1, 2, 2, 3, 4, 4, 4

Range = maximum - minimum

Range = 4 - 1 = 3

Interquartile range (IQR) :

IQR = Q3 - Q1

Q3 = 3/4(n+1)th term

Q3 = 3/4(10) = 7.5th term

Q3 = (7th + 8th) / 2 = (4+4)/2 = 4

Q1 = 1/4(10) = 2.5th term

Q1 = (2nd + 3rd) / 2

Q1 = (1 + 1) /2 = 1

Q3 - Q1 = 4 - 1 = 3