Chapter 1
What is the biggest challenge of statistical analysis?
To be able to recognize which types of analysis are most appropriate for a given situation
Can an object exist outside of its characteristics?
No, the are not independent
what shape is ideal for distribution?
Bell Shaped
Which central tendency value is the most ideal foe mathematical analysis?
The mean
Why do we subtract 1 from n in the sample variance and deviation formulas?
So we do not underestimate the population
What are the three objectives of data manipulation and organization?
Data reduction, service as an inferential measuring tool, the identification of associations or relationships among data
Which scales are qualitative?
Nominal and Ordinal
What are the four shapes we see in a distribution?
Uniform, U-shaped, J- shaped, Bell shaped
When is it the best time to use the median?
It is most appropriate to use the median when there is a skewed tendency.
What is the 68-95-99 Rule?
The percentage to SD ratio. ie 1 SD = 68
What is the difference between descriptive analysis and and inferential anaylsis?
descriptive is a direct exhaustive measurement of the population while inferential only measures the characteristics of a sample
Which scales are quantitative?
Interval and Ratio
What is the trade-off of data reduction?
We sacrafice some data to gain a larger picture
A distribution is skewed right, what can we infer about the mode, median, and mean?
The value of mode is < median and is < mean
What does the Z score accomplish?
What is the difference between univariate and multivariate analysis?
uni- focuses on one characteristic and muli- focuses on many variables simultaneous investigation
What is the difference between discrete and continuous variable?
Discrete is a finite number while continuous is infinite
What is the benefit of using a graphical presentation?
Quantity and Frequency
What is a confounding variable?
A confounding variable is a casual relationship between two variables; X and Z and their relationship impacts Y
What is statistical analysis concerned with?
"The collection, organization, and interpretation of data according to a well defined procedure"
What type of scheme is used for a numerical representation?
Scales!
True or False, the total area under a distribution curve is 100%
True
What happens when you multiply, divide, add, or subtract a constant to the central tendency
that increase or decrease by that constant
What is selection bias?
bias introduced by the way in which individuals are selected for a study/treatment