Survey Sampling and Bias
What is a survey sample?
A subset of the population used to represent the entire group.
What are the two main types of data?
Categorical
Discrete
Continuous
Define primary and secondary data.
Primary data is collected firsthand by the researcher; secondary data is collected by someone else and reused.
What is the mean of a data set and how is it found.
The average of a data set, found by adding all values and dividing by the number of values.
What is range in a data set?
The difference between the highest and lowest values in a data set.
Name two types of survey sampling techniques.
Simple random sampling and stratified sampling (other valid answers: cluster sampling, systematic sampling).
Describe qualitative and quantitative data with examples.
Qualitative data describes qualities (e.g., colors, names), while quantitative data represents quantities (e.g., height, weight).
What is a frequency distribution table.
A table that lists each data value and the number of times it occurs.
How do you find the median in an even-numbered data set?
Add the two middle numbers and divide by two.
How do you calculate variance? Its part finding the Standard Deviation
Find the mean of the data set, subtract the mean from each value, square each result, and find the average of these squares.
What is bias in a survey, and how does it affect results?
Bias is a systematic error that leads to results not accurately reflecting the population.
What type of graph would best represent categorical data?
A bar graph
Will also say Pie
How can you identify if data is skewed?
By observing whether the data leans to the left or right on a graph.
Why might mode be a useful measure in certain data sets?
Mode shows the most frequent value, useful for non-numeric data or when one value dominates.
Why is standard deviation important?
Its not is not the answer
It measures the average distance of each data point from the mean, showing data spread.
I posted a survey on facebook for my friends to answer
Voluntary response and/or Sampling Bias
What is a histogram used for?
To show the frequency distribution of continuous data.
Explain the importance of using statistical measures in analysis.
Statistical measures like mean and median help to summarize and interpret data accurately.
What does it mean if mean and median are the same?
It suggests the data may be symmetrically distributed.
Describe a normal distribution.
Bell Curve
Explain the difference between a survey population and a sample.
A population includes every member of a group being studied, while a sample is a portion of the population selected for the survey
When should you use a circle graph?
When comparing parts of a whole (especially percentages).
How do you determine if two data sets are comparable?
By comparing measures such as mean, median, and standard deviation.
Give an example where mean is a misleading measure.
Outlier
What are the key features of a skewed distribution?
Skewed distributions have one tail longer than the other, indicating data concentrated on one side.