Table of contents
- 1. Intro to Stats and Collecting Data55m
- 2. Describing Data with Tables and Graphs1h 55m
- 3. Describing Data Numerically1h 45m
- 4. Probability2h 16m
- 5. Binomial Distribution & Discrete Random Variables2h 33m
- 6. Normal Distribution and Continuous Random Variables1h 38m
- 7. Sampling Distributions & Confidence Intervals: Mean1h 3m
- 8. Sampling Distributions & Confidence Intervals: Proportion1h 12m
- 9. Hypothesis Testing for One Sample1h 1m
- 10. Hypothesis Testing for Two Samples2h 8m
- 11. Correlation48m
- 12. Regression1h 4m
- 13. Chi-Square Tests & Goodness of Fit1h 20m
- 14. ANOVA1h 0m
3. Describing Data Numerically
Standard Deviation
Problem 3.3.13
Textbook Question
Comparing Values. In Exercises 13–16, use z scores to compare the given values.
Tallest and Shortest Men The tallest adult male was Robert Wadlow, and his height was 272 cm. The shortest adult male was Chandra Bahadur Dangi, and his height was 54.6 cm. Heights of men have a mean of 174.12 cm and a standard deviation of 7.10 cm. Which of these two men has the height that is more extreme?

1
Step 1: Understand the concept of z-scores. A z-score measures how many standard deviations a data point is from the mean. It is calculated using the formula: , where is the data point, is the mean, and is the standard deviation.
Step 2: Calculate the z-score for Robert Wadlow's height (272 cm). Substitute the values into the formula: . This will give the z-score for his height.
Step 3: Calculate the z-score for Chandra Bahadur Dangi's height (54.6 cm). Substitute the values into the formula: . This will give the z-score for his height.
Step 4: Compare the absolute values of the z-scores for both individuals. The larger the absolute value of the z-score, the more extreme the data point is relative to the mean.
Step 5: Conclude which individual has the more extreme height based on the comparison of the absolute z-scores. The individual with the larger absolute z-score has the height that is more extreme.

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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Z-Score
A z-score is a statistical measurement that describes a value's relationship to the mean of a group of values. It indicates how many standard deviations an element is from the mean. A higher absolute z-score signifies a more extreme value, allowing for comparison across different datasets or distributions.
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Mean and Standard Deviation
The mean is the average of a set of values, calculated by summing all values and dividing by the number of values. The standard deviation measures the amount of variation or dispersion in a set of values. Together, these statistics provide a context for understanding how individual values relate to the overall distribution.
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Comparative Analysis
Comparative analysis involves evaluating two or more items to determine their relative positions or characteristics. In this context, it refers to assessing the heights of Robert Wadlow and Chandra Bahadur Dangi using their z-scores to identify which height is more extreme compared to the average height of men.
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