ETC1000 Study Guide - Final Guide: Type I And Type Ii Errors, Null Hypothesis, Average Weekly Earnings
31 May 2018
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Tuesday, 15 May 2018
6:24 PM
Unit Outline
1. Data Analysis
2. Description Statistics
3. Statistical Measure
4.
CPI - Consumer Price Index
Real average week earnings = nominal average weekly earnings / (CPI/100)
Descriptive Statistics
• Mean - Arithmetic Average
• Median - Middle number when data is ordered in ascendancy
• Mode - Most frequently occurring value
• Standard Deviation - Average deviation of mean.
o Variance is its square
Median may not equal mean. This causes a negative skew or a positive skew.
• Minimum: smallest value in data set
• Maximum: largest value in data set
• Range: Difference between max and min
Skewness
Left skewed (negative skewness) Right skewed (positive skewness)
*First 3 topics out of 5 are not as important
Correlation
Relationship between 2 variables.
Values ranges from -1 to 1.
Perfect Positive Correlation Perfect Negative Correlation
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No Correlation Correlation of 0.85
Confident Intervals
• How confident you are that the value/outcome will fall between 2 set of values
• 68%, 95%, 99.7% are the main values used for CI.
• The more confidence you want to have, the larger the standard deviation you should use.
• Ex. 95% confident that the maximum temp will be between 10 and 25 degrees today
o 68% = mean +/- one SD
o 95% = mean +/- two SD
o 99.7% = mean +/- three SD
Z values increase with the increase level of confidence\
Hypothesis Testing
*This is often screwed up in the exam
• Formulating a hypothesis
• Collecting data
• Examining whether the data supports the hypothesis provides evidence against it
One tailed test:
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find more resources at oneclass.com
Document Summary
Unit outline: data analysis, description statistics, statistical measure. Real average week earnings = nominal average weekly earnings / (cpi/100) Descriptive statistics: mean - arithmetic average, median - middle number when data is ordered in ascendancy, mode - most frequently occurring value. Standard deviation - average deviation of mean: variance is its square. This causes a negative skew or a positive skew: minimum: smallest value in data set, maximum: largest value in data set, range: difference between max and min. Left skewed (negative skewness) right skewed (positive skewness) *first 3 topics out of 5 are not as important. 95% confident that the maximum temp will be between 10 and 25 degrees today: 68% = mean +/- one sd, 95% = mean +/- two sd, 99. 7% = mean +/- three sd. Z values increase with the increase level of confidence\ *this is often screwed up in the exam.
