TextBook Solutions for Jharkhand Academic Council Class 11 Statistics Statistics For Economics Chapter 7 Correlation

The unit of correlation coefficient between height in feet and weight in kgs is:

• kg/feet

   

• percentage

• non-existent

The range of simple correlation coefficient is:

• 0 to infinity

   

• Minus one to plus one

   

•  Minus infinity to infinity

If r_xy is positive the relation between X an Y is of the type:

• When Y increases X increases

   

• When Y decreases X increases

•  When Y increases X does not change

If r_xy = 0 the variable X and Y are:

•  Linearly related

   

• Not linearly related

• Independent

Of the following three measures which can measure any type of relationship:

• Karl Pearson’s coefficient of correlation

   

• Spearman’s rank correlation

• Scatter diagram

If precisely measured data are available the simple correlation coefficient is:

• More accurate than rank correlation coefficient

   

•  Less accurate than rank correlation coefficient

• As accurate as the rank correlation coefficient

Why is r preferrred to co-variance as a measure of association?

Can r lie outside -1 and 1 range depending on the type of data?

Does correlation imply causation?

When is rank correlation more precise than simple correlation coefficient?