1. Design and Data Analysis in Psychology I English group (A) Salvador Chacón Moscoso Susana Sanduvete Chaves Milagrosa Sánchez Martín School of Psychology Dpt. Experimental Psychology

2. Lesson 4 Normal distribution

3.  The normal distribution is represented as the limit of a bar chart (increasing indefinitely the number of bars). 3 1. Normal distribution

4. 4 This distribution depends on 2 parameters :  and  1 1. Normal distribution: characteristics

5. 5 The normal curve has a single maximum. Mo = Mdn = 2 1. Normal distribution: characteristics

6. 6 The normal curve has 2 inflection points 3 1. Normal distribution: characteristics

7. 7 The normal curve is asymptotic to the abscissa. 4 1. Normal distribution: characteristics

8. 8 It is a symmetric distribution ( A s = 0) A s = 0 5 1. Normal distribution: characteristics

9. 9 It is a mesokurtic distribution (K r = 0). K r = 0 6 1. Normal distribution: characteristics

10. 10 The parameter gives the center of the distribution and the parameter, the variability, verifying the following relations: 1. Normal distribution

11. 11 -- -2  -3  22 33 99,7 % 95,5 % 68 % 1. Normal distribution

12. 12 1. Normal distribution

13.  It exists infinite normal distributions, each one with their means and standard deviations.  Solution: to convert raw scores into standard scores.  It implies to convert the normal distribution into a standardized normal distribution (with mean 0 and standard deviation 1). 2. Standard normal distribution 13

14. What standard distance does represent the 33.4% of data immediately over the mean? 2. Standard normal distribution: use of table, example 1 14

15. 2. Standard normal distribution: use of table, example 1 Z=0.97 15

16. In a normal distribution with mean 100 and standard deviation 15, which proportion do the values ​​ between 70 and 130 have? 2. Standard normal distribution: use of table, example 2 16

17. 2. Standard normal distribution: use of table, example 2 17

18. p=0.4772x2=0.9544 18 2. Standard normal distribution: use of table, example 2

19.  In a normal distribution with mean 100 and standard deviation 15, what raw score does define the highest 10% of data? 2. Standard normal distribution: use of table, example 3 19

20. 20 2. Standard normal distribution: use of table, example 3 10% 40% Z=1.28

21. 2. Standard normal distribution: use of table, example 3 21