Biostatistics

Question 1

estimation and hypothesis testing are what type of statistics?

Answer 1

inferential

Question 2

what is the purpose of inferential statistics?

Answer 2

make generalizations about population characteristics from incomplete data

Question 3

definition: parameters

Answer 3

measurements based on population statistics (eg mean)

Question 4

definition: statistic

Answer 4

measurements based on a sample

Question 5

definition: categorical variable

Answer 5

numeric or character codes that represent either

1. presence or absence of something that is of research interest
2. the relative weight or rank of the thing that is of research interest

Question 6

definition: process

Answer 6

1. series of actions or operations that transforms inputs to outputs
2. produces or generates output over time

Question 7

definition: nominal scale

Answer 7

categories without order

Question 8

definition: ordinal scale

Answer 8

nominal variables with an inherent order among the categories (ex stage 1, 2, 3 for cancer)

Question 9

how can qualitative variables be presented?

Answer 9

1. summary table
2. bar graph
3. pie chart

Question 10

how can quantitative variables be presented?

Answer 10

1. dot plot
2. stem and leaf
3. frequency distribution
4. histogram

Question 11

what are the two characteristics of numerical summary?

Answer 11

1. central tendency

2. variability

Question 12

what is the symbol for mean of a sample?

Answer 12

X bar

Question 13

what is the symbol for mean of a population?

Answer 13

u

Question 14

what is the symbol for size of a sample?

Answer 14

n

Question 15

what is the symbol for size of a population?

Answer 15

N

Question 16

if the mean is greater than the median what is the skew?

Answer 16

right skew

Question 17

if the mean is less than the median what is the skew?

Answer 17

left skew

Question 18

x + s contains what % of measurements?

Answer 18

68%

Question 19

x + 2s contains what % of measurements?

Answer 19

95%

Question 20

x + 3s contains what % of measurements?

Answer 20

99.7%

Question 21

what does a z score describe? what does it measure?

Answer 21

1. relative location of a measurement compared to the rest of the data
2. measures the number of standard deviations away from the mean a data value is located

Question 22

what % of of measurements have a z score between -1 and 1? -2 and 2? -3 and 3?

Answer 22

1. 68%
2. 95%
3. 99.7%