Q.24. Find out rank correlation co-efficient.
X 68 64 75 50 64
Y 62 58 68 45 81
80 75
60 68
40
48
55
50
64
70
Answers
1. CORRELATION Correlation is a statistical measurement of the relationship between two variables such that a change in one variable results a change in other variable and such variables are called correlated. Thus the correlation analysis is a mathematical tool which is used to measure the degree to which are variable is linearly related to each other
2. DIRECT OR POSITIVE CORRELATION If the increase(or decrease) in one variable results in a corresponding increase (or decrease) in the other, the correlation is said to be direct or positive. INVERSE OR NEGATIVE CORRELATION If the increase(or decrease) in one variable results in a corresponding decrease (or increase) in the other, the correlation is said to be inverse or negative correlation.
3. For example, the correlation between (i)The income and expenditure; is positive. And the correlation between (i) the volume and pressure of a perfect gas; is negative.