<span>Because sample means were being tested, the bell curve is used to calculate the z-score</span>
Step-by-step explanation:
when multiplied together, the gradients of the 2 graphs should equal -1 (of they are perpendicular).
x-7y=4
-7y= -x + 4
y= -1/7 x + 4/7
21x+ 3y=11
3y=-21x+11
y=-21/3 x + 11/3
-21/3 * -1/7 = 1
when multipled together, the 2 gradients dont equal -1 therefore they are not perpendicular
unless I've made a mistake with the signs at some point haha
Answer:

Step-by-step explanation:
4-xy=y^3
dy/dx=?

Solving for dy/dx: Addind x dy/dx both sides of the equation:

Common factor dy/dx on the right side of the equation:

Dividing both sides of the equation by 3y^2+x:

Answer:
32
Step-by-step explanation:
Answer:
y= 3x + 7 Step-by-step explanation:
y= -1/3x+3 (so, gradient of this line is -1/3).
formula: gradient of line one x gradient of line two= -1 (applies for 2 perpendicular lines only).
So, m1 x -1/3= -1
m1= (
)
m1= 3 (gradient of perp line)
y=mx+c
4= 3 x -1 + c
7=c
therefore, y=3x+7 (eqn of the line perp to y=-1/3x+3)