Use the following linear regression equation to answer the questions. x 3 = 18.2
ID: 3350900 • Letter: U
Question
Use the following linear regression equation to answer the questions.
x3 = 18.2 + 4.4x1 + 8.2x4 1.2x7
Which number is the constant term? List the coefficients with their corresponding explanatory variables.
x7 coefficient
If x1 = 3, x4 = -9, and x7 = 6, what is the predicted value for x3? (Round your answer to one decimal place.)
x3 =
Suppose x1 and x7 were held at fixed but arbitrary values.
If x4 increased by 1 unit, what would we expect the corresponding change in x3 to be?
If x4 increased by 3 units, what would be the corresponding expected change in x3?
If x4 decreased by 2 units, what would we expect for the corresponding change in x3?
(e) Suppose that n = 19 data points were used to construct the given regression equation and that the standard error for the coefficient of x4 is 0.847. Construct a 90% confidence interval for the coefficient of x4. (Round your answers to two decimal places.)
x7 coefficient
If x1 = 3, x4 = -9, and x7 = 6, what is the predicted value for x3? (Round your answer to one decimal place.)
x3 =
Suppose x1 and x7 were held at fixed but arbitrary values.
If x4 increased by 1 unit, what would we expect the corresponding change in x3 to be?
If x4 increased by 3 units, what would be the corresponding expected change in x3?
If x4 decreased by 2 units, what would we expect for the corresponding change in x3?
(e) Suppose that n = 19 data points were used to construct the given regression equation and that the standard error for the coefficient of x4 is 0.847. Construct a 90% confidence interval for the coefficient of x4. (Round your answers to two decimal places.)
(f) Using the information of part (e) and level of significance 5%, test the claim that the coefficient of x4 is different from zero. (Round your answers to two decimal places.) t = t critical = ±
Explanation / Answer
x3 = 18.2 + 4.4x1 + 8.2x4 1.2x7
Which number is the constant term? List the coefficients with their corresponding explanatory variables.
x7 coefficient -1.2
If x1 = 3, x4 = -9, and x7 = 6, what is the predicted value for x3? (Round your answer to one decimal place.)
x3 = 18.2 + 4.4x1 + 8.2x4 1.2x7
= 18.2 + 4.4*3 + 8.2 * (-9) 1.2*6 = -86
Suppose x1 and x7 were held at fixed but arbitrary values.
If x4 increased by 1 unit, what would we expect the corresponding change in x3 to be?
increase by 8.2
If x4 increased by 3 units, what would be the corresponding expected change in x3?
increase by 8.2*3 = 24.6
If x4 decreased by 2 units, what would we expect for the corresponding change in x3?
decrease by 8.2 *2 = 16.4
(e) Suppose that n = 19 data points were used to construct the given regression equation and that the standard error for the coefficient of x4 is 0.847. Construct a 90% confidence interval for the coefficient of x4. (Round your answers to two decimal places.)
df = n-k -1 = 19 -3-1 = 15
t = 1.753
we reject the null and conclude that the coefficient of x4 is different from zero.
constant -18.2 x1 coefficient 4.4 x4 coefficient 8.2x7 coefficient -1.2
If x1 = 3, x4 = -9, and x7 = 6, what is the predicted value for x3? (Round your answer to one decimal place.)
x3 = 18.2 + 4.4x1 + 8.2x4 1.2x7
= 18.2 + 4.4*3 + 8.2 * (-9) 1.2*6 = -86
Suppose x1 and x7 were held at fixed but arbitrary values.
If x4 increased by 1 unit, what would we expect the corresponding change in x3 to be?
increase by 8.2
If x4 increased by 3 units, what would be the corresponding expected change in x3?
increase by 8.2*3 = 24.6
If x4 decreased by 2 units, what would we expect for the corresponding change in x3?
decrease by 8.2 *2 = 16.4
(e) Suppose that n = 19 data points were used to construct the given regression equation and that the standard error for the coefficient of x4 is 0.847. Construct a 90% confidence interval for the coefficient of x4. (Round your answers to two decimal places.)
df = n-k -1 = 19 -3-1 = 15
t = 1.753
lower limit = (8.2 - 1.753 * 0.847) = 6.7152 upper limit = (8.2 + 1.753 * 0.847) = 9.684791(f) Using the information of part (e) and level of significance 5%, test the claim that the coefficient of x4 is different from zero. (Round your answers to two decimal places.) t = 8.2/0.847 = 9.68122 t critical = ±
2.131