What do Centurions think about our school

spirit?

Diana TapiaPeriod 3

2012-2013

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.

Hypothesis

• During this experiment, I believe the Century students will rank our school spirit between a 1 and a 2 (1 being poor and 2 being below average).

• Scale:• 1- Poor• 2- Below average• 3- Average• 4- Satisfactory• 5- Excellent

Data Collection

I collected the data based on a stratified sampling method of collecting data. I asked all grade levels, asking 25 members from each grade before school or after school.

Data

• How Century students rank our school spirit (1-5 scale)

• 1,2,1,2,3,3,3,3,3,3,3,2,1,2,3,2,1,1,1,1,1,2,2,2,2,2,2,2,3,3,1,1,1,1,1,1,2,2,2,1,3,2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,1,1,2,2,2,3,1,1,2,2,2,1,1,2,2,1,2,1,2,1,2,2,2

Statistics

• From this survey, the mean average score for our school spirit is 1.91 with a sample standard deviation of .712

Confidence Interval

• 95% Confidence Interval• Z-Interval• (1.7705~2.0495)• We are 95% confident the mean

rank Century students give for our school spirit is between 1.77 & 2.04

Hypothesis Testing

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

Hypothesis

Test Statistics

91.1:

)(91.1:0

HH

a

claim

05.09999.0 valuep

testz

H 0

Error Analysis

•The sample mean is a rank of 1.91 and the 95% confidence level for the population mean rank is between 1.7705~2.0495.•This sample error is due to the different students that were asked. Not all students have attended Century for more than a semester and some might have been absent.

Conclusion

•I created a hypothesis based on what Century students thought about our school spirit and where it ranked. I set out looking for a rank between 1 and 2 then I surveyed 100 students. The sample rank is at 1.9 with a standard deviation set at .7120 and a population mean score lying between 1.7705~2.0495. I tested the hypothesis at a 95% level of confidence with a 5% level of significance, which resulted in proving the hypothesis true.