Advertisements
Advertisements
प्रश्न
Calculate the regression equations of X on Y and Y on X from the following data:
| X | 10 | 12 | 13 | 17 | 18 |
| Y | 5 | 6 | 7 | 9 | 13 |
Advertisements
उत्तर
| X = xi | Y = yi | `"x"_"i"^2` | `"y"_"i"^2` | xi yi |
| 10 | 5 | 100 | 25 | 50 |
| 12 | 6 | 144 | 36 | 72 |
| 13 | 7 | 169 | 49 | 91 |
| 17 | 9 | 289 | 81 | 153 |
| 18 | 13 | 324 | 169 | 234 |
| 70 | 40 | 1026 | 360 | 600 |
From the table, we have,
n = 5, ∑ xi = 70, ∑ yi = 40, ∑ xi yi = 600, `sum"x"_"i"^2 = 1026`, `sum"y"_"i"^2 = 360
`bar"x" = sum"x"_"i"/"n" = 70/5 = 14`,
`bar"y" = sum"y"_"i"/"n" = 40/5 = 8`
Now, for regression equation of X on Y
`"b"_"XY" = (sum"x"_"i" "y"_"i" - "n" bar "x" bar "y")/(sum "y"_"i"^2 - "n" bar"y"^2)`
`= (600 - 5 xx 14 xx 8)/(360 - 5(8)^2) = (600 - 560)/(360 - 320) = 40/40 = 1`
Also, `"a"' = bar"x" - "b"_"XY" bar"y" = 14 - 1(8) = 14 - 8 = 6`
∴ The regression equation of X on Y is
X = a' + bXYY
∴ X = 6 + Y
Now, for regression equation of Y on X
`"b"_"YX" = (sum"x"_"i" "y"_"i" - "n" bar "x" bar "y")/(sum "x"_"i"^2 - "n" bar"x"^2)`
`= (600 - 5(14)(8))/(1026 - 5(14)^2) = (600- 560)/(1026 - 980) = 40/46 = 0.87`
Also, a = `bar"y" - "b"_"YX" bar"x"`
`= 8 - 0.87 xx 14 = 8 - 12.18 = - 4.18`
∴ The regression equation of Y on X is
Y = a + bYX X
∴ Y = - 4.18 + 0.87X
APPEARS IN
संबंधित प्रश्न
The HRD manager of a company wants to find a measure which he can use to fix the monthly income of persons applying for the job in the production department. As an experimental project, he collected data of 7 persons from that department referring to years of service and their monthly incomes.
| Years of service (X) | 11 | 7 | 9 | 5 | 8 | 6 | 10 |
| Monthly Income (₹ 1000's)(Y) | 10 | 8 | 9 | 5 | 9 | 7 | 11 |
- Find the regression equation of income on years of service.
- What initial start would you recommend for a person applying for the job after having served in a similar capacity in another company for 13 years?
The following table gives the aptitude test scores and productivity indices of 10 workers selected at random.
| Aptitude score (X) | 60 | 62 | 65 | 70 | 72 | 48 | 53 | 73 | 65 | 82 |
| Productivity Index (Y) | 68 | 60 | 62 | 80 | 85 | 40 | 52 | 62 | 60 | 81 |
Obtain the two regression equations and estimate the test score when the productivity index is 75.
Compute the appropriate regression equation for the following data:
| X [Independent Variable] |
2 | 4 | 5 | 6 | 8 | 11 |
| Y [dependent Variable] | 18 | 12 | 10 | 8 | 7 | 5 |
From the following data obtain the equation of two regression lines:
| X | 6 | 2 | 10 | 4 | 8 |
| Y | 9 | 11 | 5 | 8 | 7 |
The following sample gives the number of hours of study (X) per day for an examination and marks (Y) obtained by 12 students.
| X | 3 | 3 | 3 | 4 | 4 | 5 | 5 | 5 | 6 | 6 | 7 | 8 |
| Y | 45 | 60 | 55 | 60 | 75 | 70 | 80 | 75 | 90 | 80 | 75 | 85 |
Obtain the line of regression of marks on hours of study.
Choose the correct alternative.
If u = `("x - a")/"c" and "v" = ("y - b")/"d" "then" "b"_"yx"` = _________
Choose the correct alternative.
If u = `("x - a")/"c" and "v" = ("y - b")/"d" "then" "b"_"xy"` = _________
Choose the correct alternative.
byx = ______
Choose the correct alternative.
bxy = ______
Choose the correct alternative.
Cov (x, y) = __________
Choose the correct alternative.
If bxy < 0 and byx < 0 then 'r' is __________
Fill in the blank:
Regression equation of Y on X is_________
Fill in the blank:
There are __________ types of regression equations.
Fill in the blank:
If byx > 1 then bxy is _______
Fill in the blank:
bxy . byx = _______
Corr (x, x) = 1
Regression equation of X on Y is `("y" - bar "y") = "b"_"yx" ("x" - bar "x")`
State whether the following statement is True or False.
Corr (x, y) = Corr (y, x)
State whether the following statement is True or False.
bxy and byx are independent of change of origin and scale.
State whether the following statement is True or False.
If u = x - a and v = y - b then rxy = ruv
Compute the appropriate regression equation for the following data:
| x (Dependent Variable) | 10 | 12 | 13 | 17 | 18 |
| y (Independent Variable) | 5 | 6 | 7 | 9 | 13 |
If bxy < 0 and byx < 0 then 'r ' is ______.
