Glossary / Terminolgy

Question 1

Difference between population/census and sample

Answer 1

• The population is the complete set of objects of interest under a statistical hypothesis,
• a sample is a subset of the population

Question 2

Most proportional sampling

Answer 2

Stratified

Question 3

Advantages & disadvantages of census

Answer 3

Adv:

• completely accurate result

Disadv:

• time consuming & expensive
• cannot be used when testing process destroys the item
• hard to process large datasets

Question 4

Advantages & disadvantages of sample

Answer 4

Adv:

• less time consuming & expensive than census
• fewer responses required
• less data to process

Disadv:

• data may not be as accurate
• sample may not be large enough to give details on sub-groups of the population

Question 5

Adv of random sampling

Answer 5

Removes bias, hypothetically more representative

Question 6

Independent variable

Answer 6

Variable which you change - on x axis

Question 7

Dependent variable

Answer 7

Variable that changes depending on independent variable - on y axis

Question 8

PMCC result meanings

Answer 8

• R ≤ -0.9 = very strong negative
• -0.9 < R ≤ -0.7 = strong negative
• -0.7 < R ≤ -0.3 = moderate negative
• -0.3 < R < 0.3 = no / weak
• 0.3 ≤ R < 0.7 = moderate positive
• 0.7 ≤ R < 0.9 = strong positive
• R ≥ 0.9 = very strong positive

Question 9

Modelling assumptions for strings

Answer 9

• light / negligible mass
• inextensible

Question 10

Modelling assumptions for bodies in air

Answer 10

• modelled as particles
• no air resistance

Question 11

Equation for position vector

Answer 11

R = R_o + vt

Question 12

Independent equation

Answer 12

P(AnB) = P(A) x P(B)

Question 13

Mutually exclusive meaning

Answer 13

P(AnB) = 0

Question 14

Addition rule

Answer 14

P(AuB) = P(A) + P(B) - P(AnB)

Question 15

2 conditions necessary for a random variable being modelled by a binomial distribution

Answer 15

• fixed number of trials
• independent trials
• 2 outcomes - success and failure