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Time Centurions spend Reading. Tamika Luk and Emily Velasquez Period 2 2011-2012. CA Standards.
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Time Centurions spend Reading Tamika Luk and Emily Velasquez Period 2 2011-2012
CA Standards 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.
Hypothesis We believe that the amount a student at Century reads is less than two hours.
Data Collection Methods • We collected our data by using the random sampling method. • We split the survey in half and both asked 20 random students from each of our classes and collected a total of 4o students.
Data • Length of commute (in hours) 2, 1, 0, 1, 1, 0, 1, 3, 0.5 2, 0, 1, 1, 2, 1, 1, 1, 0, 0, 1 2, 2, 1, 1, 2, 3, 3, 1, 1, 1, 5 2, 2, 1, 3, 2, 0, 0, 3, 1
Statistics • From our survey the students at century sample mean time is 1.3875 hours with a sample standard deviation of 1.0889 hours.
Confidence Interval • 95% confidence interval • Z-interval • (1.0501~1.7249) • We are 95% confident that the mean time Centurions spend reading a day is between 1.0501 to 1.7249 hours.
Hypothesis Testing • hypothesis :We believe that the amount a student at Century reads is less than 2 hrs. • Test Statistics (Z- test): P-Value= 0.00018722 < α = .05 • Conclusion: At 5% level of significance we reject Ho. There is enough evidence to support our claim.
Error Analysis • Our sample ‘s mean is about 1.4 hours, and the 95% confidence level for the population mean is between 1.1 to 1.7 hours. The marginal error is about 0.6 hours. • Our sample error is due to possible under-representation of the population. We might need to take more samples due to student absences, we failed to ask every student at Century.
Conclusion • We hypothesized that Century students’ read a time average less than 2 hours. In our survey of 40 students, we find the sample mean of 1.3875 hours with a standard deviation of 1.0889hours. We concluded that the population mean for all students is between 1.0501 to 1.7249 hours with a 95% confidence. We test our initial hypothesis with a 5% level of significance and concluded that our hypothesis is correct.