1. Diana Mendoza Elizabeth Meza Leslie Macias Andy Rodriguez Period 6 2011-2012

2. California Standards

3. HYPOTHESIS We believe that the average applications students at Century have are 6 apps in their mobile devices.

4. DATA COLLECTION We used stratified sampling as a data collection method. Each of us asked 10 students, from freshman, sophomore, junior, and senior classes. Our possible bias is that we asked certain students we know.

5. DATA 8,10,9,15,23,27,18,15,30,12,5,4,17,4,10,6,1 2,15,7,5,6,10,12,2,4,15,3,3,4,71,6,10,15,43, 9,20,34,24,15 Number of apps (in mobile devices)

6. Histogram

7. Statistics From our survey, students sample of apps mean number is 14.3 and the standard deviation is 13.1.

8. Confidence Interval 95% Confidence Interval Z-Interval (10.146, 18.419) We are 95% confident that the number of apps that each student has are between 10.1 to 18.4.

9. Hypothesis Testing At 5% level of significance, we failed to reject the claim. There is enough evidence to support our claim. Hypothesis: Test Statistics: P-Value=0.00007<

10. ERROR ANALYSIS Our sample mean is 14.3 applications, and the 95% confidence level for the population mean is between 10.146 to 18.419 applications. Our sample error is due to possible under representation of the population. We believe that some people were not sure with the number of apps they have.

11. Conclusion We hypothesized that Century students’ average number of apps are 6. In our survey of 39 students, we found the sample mean of 14.3 apps with a standard deviation of 13.1. We conclude that the population mean for all the students is between 10.1 to 18.4. We test our initial hypothesis with 5% level of significance, and confirm our hypothesis is incorrect.