week 2 Flashcards

1
Q

What is a variable?

A

any characteristic that differs among individuals

2
Q

What is Categorical variable?

A

Categorical variable describe membership to a group are qualitative not quantitative. characteristics and do not have a magnitude orn a numerical scale.

3
Q

What is a numerical data?

A

are quantitative measurements that have magnitude on a numerical scale.

4
Q

is age at death numerical or categorical?

A

numerical

5
Q

are size classes numerical or categorical?

A

categorical

6
Q

is number of mates numerical or categorical?

A

numerical

7
Q

What is an explanatory variable?

A

The variable that predicts or affects the response variable. Is the one manipulated by the researcher.

8
Q

What is the response variable?

A

measured effect of the treatment

9
Q

What are descriptive statistics or summary statistics?

A

quantities that capture important features of frequency distributions(Standard deviation, mean)

10
Q

What is the most important descriptive statistics for categorical variables?

A

the proportion

11
Q

What do the most important descriptive statistics do?

A

measure the:
location
of a frequency distribution

12
Q

What is the sample mean?

A

The average of the measurements in the sample, the sum of all observations divided by the number of observations(n).

13
Q

What does the standard deviation measure?

A

the spread of a distribution. It indicates just how different measurements typically are from the mean.

14
Q

What is the mean?

A

the middle measurement of a set of observations

15
Q

What is the interquartile range?

A

The difference between the third and first quartiles of the data. It is the span of the middle 50% of the data.