A local trucking company fitted a regression to relate the travel time (days) of its shipments as a function of the distance traveled (miles). The fitted regression is Time = −7.126 + .0214 Distance, based on a sample of 20 shipments. The estimated standard error of the slope is 0.0053. Find the critical value for a right-tailed test to see if the slope is positive, using α = .05.

Thus; the slope is positive

Step-by-step explanation:

Given that :

the sample size = 20

for the slope; the degree of freedom df = n - 2

= 20 -2

= 18

Using ∝ = 0.05

From t -table , one tailed, at df =18)

Thus the t- critical for the right tailed test is 1.734. This simply refers to the fact that the critical region is test statistics.

Incorporating the Excel Formula [ T.INV (1 - 0.05).18) = 1.734063607

≅ 1.734

system of linear equation

step-by-step explanation:

as given in the data

a= 20 , b= -12

let us suppose that it is a straight line equation

now we know the formula for the system of linear equation

b= ma + c )

here m is slope of a straight line which is equal to formula

m=   (ii)

and here c is a constant

now putting the value of a and b in equation (ii)

m=

m=

putting the value of a,b and m in equation (i) gives us

-12 = + c

-12=-12 + c

adding 12 to both sides

-12 +12 = -12 +12 +c

0 =c

or c=0

as the value of the constant is zero which gives us that it is a linear equation and this order pair satisfies the system of linear equations.