Regressão linear calculadora hp 30s

1520 palavras 7 páginas
hp calculators

HP 30S Statistics – Linear Regression

Linear Regression Practice Solving Linear Regression Problems

hp calculators

HP 30S Statistics – Linear Regression Linear regression A regression of y on x is a way of predicting values of y when values of x are given. If the regression is based on a straight line graph, it is called a linear regression, and the straight line is called the regression line. The regression line (sometimes referred to as the line of best fit) of y on x is then the line that gives the best prediction of values of y from those of x, and is:

y = a + bx where a=

∑ y i − b∑ x i n and b =

∑ xiyi − ∑ xi2 −

∑ xi ∑ yi n (∑ x i ) 2 n

n being the number of data pairs. (Note that the regression line of x on y, which is usually different from the regression line of y on x, can be found by interchanging x and y in the above expressions). a and b are known as the linear regression coefficients. The independent variable is the regressor, and the dependent variables is called regressand. The coefficients are found by minimizing the sum of the squares of the vertical distances of the points from the line (i.e. the sum of the squares of the residuals). This method is known as least squares. The correlation coefficient is a measure of the amount of agreement between the x and y variables, and is given by:

r=

∑ xiyi −
⎛ ⎜ x 2 − (∑ x i ) ⎜∑ i n ⎝
2

∑ xi ∑ yi n 2⎞ ⎞⎛ ⎟⎜ y 2 − ( ∑ y i ) ⎟ ⎟⎜ ∑ i n ⎟ ⎠⎝ ⎠

When r is positive, the correlation is positive, which means that high values of one variable correspond to high values of the other. Conversely, if r is negative then the correlation is negative: low values of one variable correspond to high values of the other. An important property of r is that − 1 ≤ r ≤ 1 . The ±1 values correspond to a perfect correlation: real values and estimates are exactly the same. If r = 0 then there’s no correlation: x and y are uncorrelated. On the HP 30S, linear regressions

Relacionados

  • Uso da hp
    3081 palavras | 13 páginas
  • Diversos
    4360 palavras | 18 páginas
  • hp50g
    16540 palavras | 67 páginas
  • Engenharia
    2762 palavras | 12 páginas
  • APOSTILAPSICOLOGIA
    17673 palavras | 71 páginas
  • Curso hp 12c
    7140 palavras | 29 páginas
  • Meu cachorro
    2123 palavras | 9 páginas
  • Matematica hp 12 c
    8254 palavras | 34 páginas
  • hp 50c
    20189 palavras | 81 páginas
  • MAtematica
    5939 palavras | 24 páginas