Stats general small things

Question 1

Regression line of y on x

Answer 1

y = a + bx

b= change in y for each unit change in x positive

value of b = positive correlation a=y when x=0

Question 2

Conditions for a binomial distribution

Answer 2

• Fixed number of trials (n)
• 2 possible outcomes
• Fixed probability of success (p)
• Trials are independant

Question 3

Conditions and equations used for approximating a binomial distribution

Answer 3

n is large

p is close to 0.5

µ = np

σ² = npq

Question 4

Histogram equations

Answer 4

area ∝ frequency

A = k x f

FD = f / CW

Question 5

To prove events are independant

Answer 5

P (A and B) = P (A) × P(B)

P(A|B) = P(A)

Question 6

And rule for conditional probability

Answer 6

P(A and B) = P(A) × P(B|A)

Question 7

Rule for resolving forces

Question 8

Moments equation

Answer 8

force × perpendicular distance from the force

Question 9

Friction equations

Answer 9

F ≤ µR

F_max = µR

Question 11

Equations used for projectiles

Answer 11

s = ut + ½at²

v = u + at

Question 12

Equation used for vectors with constant velocity

Answer 12

r = vt + r₀

r: displacement

r₀ = position vector at start