How many times do you shop in a month?

Jacquelin Gonzalez Period: 6(2011-2012)

California 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 statistics for a simple random sample from a normal distribution.

I hypothesis that people shop around 6 times a month.

Hypothesis

Data Collection•I collected the data by using stratify sampling method.

•I asked 10 freshman, 10 sophomores, 10 juniors, and 10 seniors. The total of students I asked were 40.

Data•Times shopping in a month.•5, 8, 7, 5, 9, 12, 10, 4, 4, 8, 5, 8, 5, 7, 5, 4, 6, 3, 5, 3, 2, 10, 12, 11, 10, 5, 4, 5, 5, 7, 5,. 4, 6, 10, 6, 9, 6, 7, 6, 5.

Histogram

2.5 4 6 7.5 9 11 12.50

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4

6

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14

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How many times do you shop in a month?

# of times

# of

stud

ents

Statistics•From my survey, how many times do students go shopping in a month is 6.45 times with sample standard deviation 2.5414 times.

Confidence Interval• 95%Cofidence Interval• Z- Interval• (5.6624, 7.2376)• I am 95% confident that the mean of

shopping in a month is between 5.66 to 7.23.

Hypothesis TestingClaim: I believed that the number of time centurions go

shopping in a month is 6.

P-Value= .2627671971<x=0.05

At 5% level of significance we fail to reject the Ho.There is enough evidence to support our claim (Hypothesis.)

6:)(6:0

aHclaimH

Error Analysis• My sample mean is 6.45, and the 95%

confidence level for the population mean is between 5.66 to 7.23. The marginal error is about .79 times.

• My sample error is due to possible under-representation of the population. I might missed some students that were absent the day I asked the question or the students might have lied.

ConclusionI hypothesized that students from Century High

School shopping in a month average is 6 times. In a survey of 40 students, I find the sample mean of 6.45 times with a standard deviation of 2.5414

times. I conclude that the total of times students shop in a month, is between 5.66 to 7.23 times with the 95% confident. I tested my initial hypothesis with

5% level of significance, and confirmed my hypothesis is correct.

THE END