1. How many hours do guys play video games a day? Efrain Arriaga, Victor Salgado, Victor Figueroa, Franco Figueroa Period 3 2012 - 1213

2. California Standards 8.0 Student organized and describe distribution of data by using of different methods, including frequency table, histogram, standard line and bar graphs, stem-and-leaf displays, scatter plots, and box of whisker plots. 17.0 Students determine confidence interval for a simple random sample from a normal distribution of data and determine the sample size required for a desired margin of error. 18.0 Student determine the P-value for a statistic for a simple random sample from a normal distribution

3. Hypothesis We predict that the average guys play video games a day is between is between 2-3 hours

4. Data Collection We used stratified sampling technique, we asked 100 students. We chose 25 students from each grade Example: We will collect data by using the stratified sampling method. We collected data from students chose by us and divide it into freshman, sophomore, juniors and seniors.

5. Data Freshmans:6,4,0,0,1,3,7,2,3,2,3,1,2,2,2,3,5,4, 3,3,0,3,2,3,3 Sophomores:3,1,3,4,2,1,1,3,1,1,1,2,3,1,2,3,4, 5,2,3,1,2,4,3 Juniors:3,2,3,2,4,2,0,0,0,1,2,4,5,3,2,2,2,1,2,3,4,2,1,3,4,2 Senior:2,3,0,0,2,2,1,0,1,4,1,3,2,4,5,0,0,2,1,3, 4,3,2,2,1

6. Statistics From our survey student’s sample mean time is 2.29 hours with sample standard deviation 1.430349608 hours.

7. Confidence Interval We are 95% confident the mean hours guys play video games is between 2.0097~2.5703

8. Hypothesis Testing Hypothesis Test Statistics At 5% level of significance, we failed to reject. There is enough evidence to support our claim.

9. Error Analysis Our sample mean is 2.29 hours, and the 95% confidence level for the population mean is between 2.0097~2.5703 hours. The marginal error is about 5% minutes. Our sample error is due to possible under-representation of the population. We might need to take more samples due to student absences.

10. Conclusion We hypothesized that Century students play 2-3 hours of video games daily. survey of 100 male students, we find the sample mean 2.29 We were slightly correct.