<span>Vector Equation
(Line)</span>(x,y) = (x,y) + t(a,b);tERParametric Formx = x + t(a), y = y + t(b); tERr = (-4,-2) + t((-3,5);tERFind the vector equation of the line passing through A(-4,-2) & parallel to m = (-3,5)<span>Point: (2,5)
Create a direction vector: AB = (-1 - 2, 4 - 5)
= (-3,-1) or (3,1)when -1 (or any scalar multiple) is divided out.
r = (2,5) + t(-3,-1);tER</span>Find the vector equation of the line passing through A(2,5) & B(-1,4)<span>x = 4 - 3t
y = -2 + 5t
;tER</span>Write the parametric equations of the line passing through the line passing through the point A(4,-2) & with a direction vector of m =(-3,5)<span>Create Vector Equation first:
AB = (2,8)
Point: (4,-3)
r = (4,-3) + (2,8); tER
x = 4 + 2t
y = -3 + 8t
;tER</span>Write the parametric equations of the line through A(4,-3) & B(6,5)<span>Make parametric equations:
x = 5 + 4t
y = -2 + 3t ; tER
For x sub in -3
-3 = 5 + 4t
(-8 - 5)/4 = t
-2 = t
For y sub in -8
-8 = -2 + 3t
(-8 + 2)/3 = t
-2 = t
Parameter 't' is consistent so pt(-3,-8) is on the line.</span>Given the equation r = (5,-2) + t(4,3);tER, is (-3,-8) on the line?<span>Make parametric equations:
x = 5 + 4t
y = -2 + 3t ; tER
For x sub in 1
-1 = 5 + 4t
(-1 - 5)/4 = t
-1 = t
For y sub in -7
-7 = -2 + 3t
(-7 + 2)/3 = t
-5/3 = t
Parameter 't' is inconsistent so pt(1,-7) is not on the line.</span>Given the equation r = (5,-2) + t(4,3);tER, is (1,-7) on the line?<span>Use parametric equations when generating points:
x = 5 + 4t
y = -2 + 3t ;tER
X-int:
sub in y = 0
0 = -2 + 3t
solve for t
2/3 = t (this is the parameter that will generate the x-int)
Sub t = 2/3 into x = 5 + 4t
x = 5 + 4(2/3)
x = 5 + (8/3)
x = 15/3 + (8/3)
x = 23/3
The x-int is (23/3, 0)</span>What is the x-int of the line r = (5,-2) + t(4,3); tER?Note: if they define the same line: 1) Are their direction vectors scalar multiples? 2) Check the point of one equation in the other equation (LS = RS if point is subbed in)What are the two requirements for 2 lines to define the same line?
Answer:
The point estimate used to estimate the mean height of all adult males in Idaho is 69.505 inches.
Step-by-step explanation:
Each confidence interval has two bounds, the lower bound and the upper bound. The points estimate used to estimate the mean is the halfway point between those two bounds, that is, the sum of those two bounds divided by two.
In this problem, we have that:
Lower bound: 62.532
Upper bound: 76.478
Point estimate: (62.532 + 76.478)/2 = 69.505
The point estimate used to estimate the mean height of all adult males in Idaho is 69.505 inches.
Let's say we wanted to subtract these measurements.
We can do the calculation exactly:
45.367 - 43.43 = 1.937
But let's take the idea that measurements were rounded to that last decimal place.
So 45.367 might be as small as 45.3665 or as large as 45.3675.
Similarly 43.43 might be as small as 43.425 or as large as 43.435.
So our difference may be as large as
45.3675 - 43.425 = 1.9425
or as small as
45.3665 - 43.435 = 1.9315
If we express our answer as 1.937 that means we're saying the true measurement is between 1.9365 and 1.9375. Since we determined our true measurement was between 1.9313 and 1.9425, the measurement with more digits overestimates the accuracy.
The usual rule is to when we add or subtract to express the result to the accuracy our least accurate measurement, here two decimal places.
We get 1.94 so an imputed range between 1.935 and 1.945. Our actual range doesn't exactly line up with this, so we're only approximating the error, but the approximate inaccuracy is maintained.
