Computing as Experiment

Question 1

What is the variance equation?

Answer 1

var(x) = ∑(x∈Ω)▒(r(X)-E[X])^2
where r(X) is the random variable
E[X] is the expected value
x∈Ω means x in population

Question 2

What is the equation for expected value of a random variable?

Answer 2

E[X] = ∑(x∈Ω)▒〖P[X]r(X)〗
P[X] is probability of X
r(X) is random variable
x∈Ω means x in population

Question 3

What does variance show?

Answer 3

How spread out values in a population are

Question 4

What is the equation for standard deviation?

Answer 4

σ=√var(X)

Question 5

Why is standard deviation in practice usually an estimate rather than a correct value?

Answer 5

Finding the variance for the standard deviation equation requires surveying every member of a population which is non-faesible so instead we estimate via sampling

Question 6

How do we do significance testing?

Answer 6

Count the number of standard deviations between predicted outcome X and actual outcome Y