Number of Apps for Century Students

Diana MendozaElizabeth MezaLeslie MaciasAndy RodriguezPeriod 62011-2012

8.0 Students organize and describe distributions of data by using a number of different methods, including frequency tables, histograms, standard line and bar graphs, stem-and-leaf displays, scatter plots, and box-and-whisker plots.

17.0 Students determine confidence intervals 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 Students determine the P-value for a statistic for a simple random sample from a normal distribution.

California Standards

HYPOTHESIS

We believe that the average applications students at Century have

are 6 apps in their mobile devices.

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.

DATA

8,10,9,15,23,27,18,15,30,12,5,4,17,4,10,6,12,15,7,5,6,10,12,2,4,15,3,3,4,71,6,10,15,43,9,20,34,24,15

Number of apps (in mobile devices)

7.75 19.25 30.75 42.25 53.75 65.25 76.750

5

10

15

20

25Number of Apps

Number of Applications

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Histogram

StatisticsFrom our survey, students

sample of apps mean number is 14.3 and the standard deviation is 13.1.

Confidence Interval95% Confidence IntervalZ-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.

Hypothesis Testing

At 5% level of significance, we failed to reject the claim. There is enough evidence to support our claim.

)(6:0 claimH 6: H

Hypothesis:

Test Statistics:P-Value=0.00007<

06.0

06.0

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.

ConclusionWe 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.