2. Holt McDougal Algebra 2 Significance of Experimental Results How do we use tables to estimate areas under normal curves? How do we recognize data sets that are not normal?

3. Holt McDougal Algebra 2 Significance of Experimental Results Standard Deviation of a Data Set A normal distribution with mean x and standard deviation  has these properties: x x –  x +  x – 2  x + 2  x – 3  x + 3  68% 95% 99.7% The total area under the related normal curve is ____. About ___% of the area lies within 1 standard deviation of the mean. About ___% of the area lies within 2 standard deviation of the mean. About _____% of the area lies within 3 standard deviation of the mean. 1 68 95 99.7 34% 13.5% 2.35% 0.15% x x –  x +  x – 2  x + 2  x – 3  x + 3  0.15%

4. Holt McDougal Algebra 2 Significance of Experimental Results Find a normal probability 1.A normal distribution has a mean x and standard deviation . For a randomly selected x- value from the distribution, find x x –  x +  x – 2  x + 2  x – 3  x + 3 

5. Holt McDougal Algebra 2 Significance of Experimental Results Interpret normally distributed data 2.The math scores of an exam are normally distributed with a mean of 518 and a standard deviation of 115. 518 633748 863403288173 a.About what percent of the test-takers have scores between 518 and 748? b.About what percent of the test-takers have scores less than 403? c.About what percent of the test-takers have scores between 403 and 633?

6. Holt McDougal Algebra 2 Significance of Experimental Results Interpret normally distributed data. 3.The heights (in feet) of fully grown white oak trees are normally distributed with a mean of 90 feet and a standard deviation of 3.5 feet. 90 93.597 100.5 86.5 8379.5 ? a.About what probability of white oak trees have heights between 86.5 feet and 93.5 feet? ? b.About what probability of white oak trees have heights between 79.5 feet and 86.5 feet? ? c.About what probability of white oak trees have heights greater than 93.5 feet?

7. Holt McDougal Algebra 2 Measures of Central Tendency and Variation Lesson 2.3 Practice A

8. Holt McDougal Algebra 2 Significance of Experimental Results 7. 8. 9.10.