Module 2: Biostatistics

Question 1

What is the overlying reason we need statistics in health sciences?

Answer 1

To understand the health of a population

Question 2

What is the percentage of 6/10, and what is the proportion?

Answer 2

60%

0.6

Question 3

What is the maximum possible proportion?

Answer 3

1

Question 4

Population

Answer 4

The group we’re interested in

Question 5

Sample

Answer 5

Small group from population

Question 6

What can we do with a sample?

Answer 6

Investigate it and use it to make an inference about the population

Question 7

Standard deviation

Answer 7

A measure of the spread of data points in a sample

How far away, on average, the data is from the mean

Question 8

A larger sample size will cause a ____ deviation?

What does this mean for our investigation?

Answer 8

Narrower

We have more certainty in our answers

Question 9

Categorical variable

Answer 9

A variable which has a set number of possibilities

Question 10

Continuous variable

Answer 10

A variable that can take on any value

Question 11

Estimate + or - 1.96 x SE

Is the equation for what?

Answer 11

95% confidence interval

Question 12

What does 1.96SE from the true population mean include?

Answer 12

95% of all sample means

Question 13

Is it correct to say the 95% confidence interval gives a 95% chance of the answer lying within the interval?

Answer 13

No, we are 95% confident it does

Question 14

What are the two parameters of the confidence interval called?

Answer 14

Lower confidence limit

Upper confidence limit

Question 15

Will the sample’s 95% confidence interval include the true population mean?

Answer 15

Most of the time (95% of samples)

Question 16

Median

Answer 16

Line where 50% of sample lies below, and 50% above

Question 17

25th percentile

Answer 17

Line where 25% of sample lies below

Question 18

75th percentile

Answer 18

Line where 25% of sample lies above

Question 19

Bias

Answer 19

Error which moves us away from the truth

Question 20

Two types of error

Answer 20

Errors that make our answers more uncertain

Errors that move us away from the truth

Question 21

How do we minimise errors that add variability? (2)

Answer 21

Use same measuring system

Make other variables constant

Question 22

How do we best avoid bias?

Answer 22

Take a random sample from the population

Question 23

Convenience sample- what’s wrong with it?

Answer 23

Sample isn’t truly random. It misses reaching everyone who isn’t convenient to contact

Question 24

Standard error

Answer 24

Variability of sampling distribution

Measures how far away the sample means are from the population mean

Question 25

μ

Answer 25

Population mean

Question 26

σ

Answer 26

Population standard deviation

Question 27

x̄

Answer 27

Sample mean

Question 28

n

Answer 28

Sample size

Question 29

s

Answer 29

Sample standard deviation

Question 30

What shape does the sampling distribution follow with a large sample size?

Answer 30

Bell shaped curve

Question 31

y = a + bx

Answer 31

Formula for regression line