1. If dots are lying on a scatter diagram in a haphazard manner, then r = ………………….
A. 0
B. +1
C. –1
D. None of these
2. If all the points of a dot chart lie on a straight line parallel to the X-axis, it denotes ……………… of correlation.
A. High degree
B. Low degree
C. Moderate degree
D. Absence
3. Scatter diagram is also known as
A. Dot chart
B. Correlation graph
C. Both (a) and (b)
D. None of these
4. If the dots in a scatter diagram fall on a narrow band, it indicates a ………………. degree of correlation.
A. Zero
B. High
C. Low
D. None of these
5. If all the points of a scatter diagram lie on a straight line falling from left upper corner to the right bottom corner, the correlation is called……………….
A. Zero correlation
B. High degree of positive correlation
C. Perfect negative correlation
D. Perfect positive correlation
6. If all the points of a dot chart lie on a straight line vertical to the X-axis, then coefficient of correlation is ……………….
A. 0
B. +1
C. –1
D. None of these
7. If the amount of variations in variable X bears a constant ratio to the corresponding amount of variations in Y, then the relationship between them is said to be
A. Linear correlation
B. Non-linear correlation
C. Either (a) or (b)
D. None of the above
8. If all the dots of a scatter diagram lie on a straight line falling from left bottom corner to the right upper corner, the correlation is called………………
A. High degree of positive correlation
B. Zero correlation
C. Perfect negative correlation
D. Perfect positive correlation
9. In case of scatter diagrams
A. Different sets of data are plotted on a graph
B. We can observe patterns between variables that indicate whether the variables are related.
C. If the variables are related, we can get an idea of the type of relationship that exists
D. All of the above
10. If Y is unaffected by any change in X variable, then the relationship between them is said to be
A. Un-correlated
B. Negative correlation
C. Positive correlation
D. Linear correlation
11. The unit of Coefficient of correlation is ……………………
A. Percentage
B. Ratio
C. Same unit of the data
D. No unit
12. Which of the following is true for coefficient of correlation?
A. It is a dimensionless number whose numerical value lies between +1 to 1
B. It is a pure number and is independent of the units of measurement of the variables.
C. It is independent of any change in the origin and scale of X and Y values.
D. All of the above
13. When correlation exists between two seemingly unrelated variables, it is called
A. Spurious
B. Non- sense correlation
C. Neither (a) nor (b)
D. Both (a) and (b)
14. If r= +1, the correlation is said to be ……………….
A. High degree of +ve correlation
B. High degree of –ve correlation
C. Perfect +ve correlation
D. Perfect –ve correlation
15. Coefficient of correlation explains …………………….of the relationship between two variables
A. Degree
B. Direction
C. Both of the above
D. None of the above
16. Product moment correlation method is also
A. Rank correlation
B. Concurrent deviation
C. Pearsonian correlation
D. None of the above
17. Rank correlation coefficient was discovered by
A. Fisher
B. Karl Pearson
C. Bowley
D. Spearman
18. The rank correlation coefficient is always
A. + 1
B. – 1
C. Between + 1 and – 1
C. 0
19. For perfect correlation, the coefficient of correlation should
A. ± 1
B. + 1
C. – 1
D. 0
20. If r = 0.8, coefficient of determination is……………………………….
A. 80%
B. 8%
C. 80%
D. 64%