# Stats Test 1

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1. What is an element?
The entites on which data are collected

EX: Name on the cities in data
2. What is a variable?
A characteristic of interest for the elements

EX: Hi, Lo, Condition
3. What is an obersvation?
The set of measurements obtained for a particular element
4. Data Values=
# of variables X # of elements
5. Ordinal
The data have the properties of nominal data and the order or rank of the data is meangful

A nonnumeric label or numeric code may be used

EX: Freshmen(1), Sophomore(2), Junior(3), or Senior(4)
6. Nominal
Data are LABES OR NAMES used to identify an attribute of the element

A nonnumeric label or numeric code may be used
7. Interval
The data have the properties of ordinal data, and the interval between observations is expressed in terms of a fixed unit of measure

Melissa scored an 1885, Kevin scored a 1780, Melissa scored 105 points better than Kevin
8. Ratio
The data have all the properties of interval data and the ratio of two is meaningful

Variables such as distance, height, weight, and time
9. Categorical Data (Qualitative Data)
Labels or names used to identify an attribute of each element
10. Quantitative Data
• Data indicating how many or how much
• - Discrete- measuring how many
• - Continous- measuring how much

Always numeric
11. Observational Studies-
No attempt to control or influence the variables of interest
12. Experimental Studies-
Variables of interest of identified at different times, so they can see how each influences the outcome
13. Frequency Distribution-
A tabular summary of data showing the frequency of items in each of several non-overlapping classes
14. Relative Frequency
Frequency / total sample size
15. Clas Width=
Largest Data Value - Smallest Data Value / Number of Classes
16. Skewed Right
Longer tail to the right

Mean will be more than the median
17. Skewed Left
Longer tail to the left

Mean will be less than the median
18. Means
Sample mean = Population mean= 19. Trimmed mean
Deleting a % of the smallest and largest values from a data set and then computing the mean of the reamaining values
20. Percentile formula
i= (p/100)n

• p= percentile
• n= sample size
21. Range=
Largest value - smallest value
22. Interquartile Range (IQR)
Q3-Q1
23. The variance?
The average of the squared differences b/t each data value and the mean
24. Standard Deviation?
The positive square root of the variance
25. Correlation Coefficient
Can take on values between -1 and +1

The closer it is to 0, the weaker the relationship
26. Arthimetic operations are inappropiate for..
the nominal scale
27. Statistical studes in which researchers do not control variables of interest are..
observational studies
28. Gender is an example of _____ data..
Nominal
29. The measure of lovation which is the most likely to be influenced by extreme values n the data set is..
Mean
30. What is a measure of dispersion?
Interquartile range (IQR)
31. The descriptive measure of dispersion that is based on the concept of a deviation about the mean is?
The standard deviation
32. The numberical value of the standard deviation can never be..
Negative
33. The measure of dispersion which is not measured in the same units as the original data is the..
Variance
34. A numerical measure of linear association b/t two variables is the..
Covariance
35. The coefficient of correlation..
cannot be larger than 1
36. Data collected over several time periods are..
Time series data
 Author: Calittlefield ID: 157456 Card Set: Stats Test 1 Updated: 2012-06-05 23:52:42 Tags: Stats Test Folders: Description: Note Cars for Stats Test 1 Show Answers: