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
2. Describing Data with Tables and Graphs
Histograms
Problem 2.3.6
Textbook Question
In Exercises 5 and 6, construct the dotplot.
Diastolic Blood Pressure Listed below are diastolic blood pressure measurements (mm Hg) of females selected from Data Set 1 “Body Data†in Appendix B. All of the values are even numbers. Are there any outliers? If so, identify their values.


1
Step 1: Organize the data in ascending order. This will make it easier to construct the dotplot and identify any potential outliers. The data is: 60, 60, 62, 62, 64, 66, 68, 70, 70, 70, 70, 72, 74, 76, 76, 78, 78, 82, 82, 84, 86, 88, 90, 90.
Step 2: Construct a dotplot. For each unique value in the data set, place a dot above the corresponding value on a number line. If a value appears multiple times, stack the dots vertically.
Step 3: Calculate the interquartile range (IQR) to identify potential outliers. First, find the first quartile (Q1) and third quartile (Q3). Q1 is the median of the lower half of the data, and Q3 is the median of the upper half. Then, compute the IQR as IQR = Q3 - Q1.
Step 4: Determine the outlier boundaries. Use the formula: Lower boundary = Q1 - 1.5 * IQR and Upper boundary = Q3 + 1.5 * IQR. Any data points outside these boundaries are considered outliers.
Step 5: Compare the data points to the outlier boundaries. Identify any values that fall below the lower boundary or above the upper boundary. These values are the outliers, if any exist.

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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Dotplot
A dotplot is a simple graphical display used to represent the distribution of a dataset. Each data point is represented by a dot above its corresponding value on a number line. This visualization helps in identifying patterns, clusters, and potential outliers in the data, making it easier to analyze the overall distribution.
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Outliers
Outliers are data points that significantly differ from the other observations in a dataset. They can be unusually high or low values that may indicate variability in the measurement or errors in data collection. Identifying outliers is crucial as they can skew statistical analyses and affect the interpretation of results.
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Diastolic Blood Pressure
Diastolic blood pressure is the pressure in the arteries when the heart rests between beats. It is one of the two measurements used to assess blood pressure, the other being systolic blood pressure. Understanding diastolic blood pressure is important in evaluating cardiovascular health and identifying potential health risks.
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