Transcript How many times do a student get detention per month?

Pedro Mendoza
Agustin Ocampo
Period 6
2011-2012
CA Standard
8.0 Students organized and describe distribution of data by using a number of
different methods, including frequency gables, histograms, standard line
and bar graphs, stem-and-leaf displays, Scatter plots, and box-and-whisker
plots.
17.0 Students determine confidence intervals for simple random sample
from a normal distribution of data determine the sample size required for a
desired margin error.
18.0 Students determine the P-value for a statistics for a simple random
sample from a normal distribution
Hypothesis
 (claim) we believe that the number of times do a
student get detention is 2 times
Data Collection
 (cluster sample and systematic sampling)
 We collected data by using the cluster sample method.
We asked 20 seniors each one of us for a total of 40
seniors. Then, we use systematic sampling by asking
every 5th seniors how many times do they get detention
per month?
Data
 Length of detention (per month)
 1, 2, 2, 1, 1, 3, 1, 1, 2, 1, 2, 1, 3, 2, 1, 1, 2, 2, 1, 3, 1, 5, 3, 2, 1, 1,
1, 2, 2, 1, 4, 1, 2, 3, 2, 1, 3, 4, 5, 1,
Histogram
Detention
20
18
Number of students
16
14
12
10
8
6
4
2
0
1
1.5
2.5
3
3.5
Number of times
4.5
5
5.5
Statistics
 From our survey, students sample detention mean
time is 1.925 with sample standard deviation 1.1410
Confidence Interval
 95% Confidence Interval
 Z-Interval
 (1. 5714, 2. 2785)
 We are 95% confidence mean times do a student get
detention per month is between 1.5 to 2.2
Z Test
 H 0 :   2(claim )
 Ha :   2
 P-value = 0. 6776 >
= 0. 05
 At 5% level of significance, we failed to reject the .
There is enough evidence to support the claim
Error Analysis
 Our sample mean is 1. 925 times, and the 95%
confidence level of the population mean is between 1.
5714 to 2. 2785 times. The marginal error is about 0.
3536 times
 Our sample error is due to possible
underrepresentation is because students were absents
or students lied.
Conclusion
 We hypothesized that Century students’ detention
time average is 2 times per month. In our survey of 40
students, we find the sample mean of 1. 92 with a
standard deviation of 1. 14. We conclude that the
population mean for all the students is between 1. 5 to
2.5 with 95% confident. We test our initial hypothesis
with 5% level of significance, and confirm our
hypothesis is incorrect