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
6. Normal Distribution and Continuous Random Variables
Standard Normal Distribution
Problem 3.CRE.7
Textbook Question
Normal Distribution Examine the distribution shown in the histogram from Exercise 6. Does it appear that the sample data are from a population with a normal distribution? Why or why not?


1
Step 1: Observe the histogram provided. A normal distribution typically has a bell-shaped curve, where the frequencies are highest at the center and taper off symmetrically towards the tails. In this histogram, the frequencies do not follow this pattern.
Step 2: Note the peaks and troughs in the histogram. For a normal distribution, the frequencies should gradually decrease as you move away from the center. However, the histogram shows irregular peaks, such as the high frequency at digit 5 and lower frequencies at digits 3 and 4.
Step 3: Assess the symmetry of the distribution. A normal distribution is symmetric around its mean. In this histogram, the frequencies are not symmetric; for example, the frequencies for digits 0, 1, and 2 differ significantly from those for digits 7, 8, and 9.
Step 4: Consider the spread of the data. A normal distribution has a smooth, continuous spread. The histogram here shows a jagged pattern with abrupt changes in frequency, which is inconsistent with a normal distribution.
Step 5: Conclude based on the observations. The irregular shape, lack of symmetry, and uneven spread of frequencies suggest that the sample data are not from a population with a normal distribution.

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