The data below are the gestation periods, in months, of randomly selected animals and their corresponding life spans, in years.

Gestation, x 8 2.1 1.3 1 11.5 5.3 3.8 24.3
Life span, y 30 12 6 3 25 12 10 40

a. Find the equation of the regression line for the given data. Round the line values to the nearest two decimal places. Show your work.


b. Using the equation found in part a, predict the life span when the gestation is 10 months. Round to the nearest absence.

Respuesta :

Answer:

(a) The regression line is: y = 6.343 + 1.523 x

(b) For a gestation period of 10 months, the life span is 22 years.

Step-by-step explanation:

The regression line is of the form: y = a + b x.

Here,

y = dependent variable = life span of animals

x = independent variable = gestation periods

a = intercept

  [tex]=\frac{\sum Y.\sum X^{2}-\sum X\sum XY}{n.\sum X^{2}-(\sum X)^{2}}[/tex]

b = slope

  [tex]=\frac{n.\sum XY-\sum X\sum Y}{n.\sum X^{2}-(\sum X)^{2}}[/tex]

(a)

Compute the value of intercept as follows:

[tex]a=\frac{\sum Y.\sum X^{2}-\sum X\sum XY}{n.\sum X^{2}-(\sum X)^{2}}=\frac{(138\times836.37)-(57.3\times1637.1)}{(8\times836.37)-(57.3)^{2}} =6.343[/tex]

The intercept is 6.343.

Compute the value of slope as follows:

[tex]b=\frac{n.\sum XY-\sum X\sum Y}{n.\sum X^{2}-(\sum X)^{2}}=\frac{(138\times1637.1)-(57.3\times138)}{(8\times836.37)-(57.3)^{2}} =1.523[/tex]

The slope is 1.523.

The regression line is:

y = 6.343 + 1.523 x

(b)

Foe x = 10 compute the value of y as follows:

[tex]y = 6.343 + 1.523 x\\=6.343+(1.523\times10)\\=21.573\\\approx22[/tex]

Thus, for a gestation period of 10 months, the life span is 22 years.

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