Name Nandita Ghosh
Class time 64Z -Online
Find an article in a newspaper, magazine or on the internet which makes a claim about
ONE population mean or ONE population proportion.
Copy or print out the article and include a copy in your project, along with the source.
The article can be found at
Claim : 32% of children and teens are obese or overweight,
State how you will collect your data. (Convenience sampling is not acceptable.)
I will search online for this data. I will use stratified sampling by dividing US into different states or strata
I will collect data containing the percentage of children obese per state in the US
Conduct your survey. You must have more than 50 responses in your sample.
When you hand in your final project, attach the tally sheet or the packet of questionnaires
I got the data for the survery from here
State the statistics that are a result of your data collection: sample size, sample mean, and sample s
sample size : 51
sample mean : 14.29%
sample standard deviation : 0.0321
Make 2 copies of the appropriate solution sheet.
Record the hypothesis test on the solution sheet, based on your experiment. Do a DRAFT
solution first on one of the solution sheets and check it over carefully. Have a classmate
check your solution to see if it is done correctly. Make your decision using a 5% level of
The solution sheet can be accessed :
Create a graph that illustrates your data.
This may be a pie or bar chart or may be a histogram or box plot, depending on the nature
of your data. Produce a graph that makes sense for your data and gives useful visual
information about your data. You may need to look at several types of graphs before you
I have created a histogram to display the data . Please find the histogram here :
Write your summary (in complete sentences and paragraphs, with proper grammar and correct spel
1. Brief discussion of the article, including the source.
Source of the article :
This article is about the issue of obesity in children.
Obsese children are at a higher risk to die early from different diseases such as cardiac, liver and
2. Statement of the claim made in the article (one of the hypotheses).
The claim in the article is that 32% of children and teens in the US are obese
3. Detailed description of how, where, and when you collected the data, including the
Did you use cluster, stratified, systematic, or simple random sampling (using a random
I used stratified sampling. Since I wanted to calculate data all over the US, I sampled data for all the states in
4. Conclusion about the article claim in light of your hypothesis test.
This is the conclusion of your hypothesis test, stated in words, in the context of the
situation in your project in sentence form, as if you were writing this conclusion for a non-
From the hypothesis test we can conclude that the claim in the article that the percentage of obese
children in US =32% is incorrect.
5. Sentence interpreting your confidence interval in the context of the situation in your project.
We are 95% confident that the true population mean of the average percentage of obese children in US is betw
states or strata
mean, and sample standard deviation, OR sample size and number of successes.
ar and correct spelling) that describes the project. The summary MUST include:
for all the states in the US
n your project.
hildren in US is between 14.281% and 14.299%
a. H o : u = 32% of children in US are obsese
b. H a : u is not = 32%
c. In words, CLEARLY state what your random variable X or P' represents.
X bar represents the % of children who are obese in the US
d. State the distribution to use for the test.
Student-T distribution will be used for this test since we don’t know the population standard
X bar ~ t df where df = n-1
Hence X bar ~ t50
e. What is the test statistic?
Test statistic is x bar= 14.29%
f. What is the p -value? In 1 – 2 complete sentences, explain what the p -value means for
p-value is 0
If the null hypothesis is true there is a 0 probability that the sample mean is 14.29% or less
OR 49.71% or more
g. Use the previous information to sketch a picture of this situation. CLEARLY, label and
scale the horizontal axis and shade the region(s) corresponding to the p -value.
h. Indicate the correct decision (“reject” or “do not reject” the null hypothesis), the reason
for it, and write an appropriate conclusion, using complete sentences.
i. Alpha: 0.05
ii. Decision: Reject the Null Hypothesis
iii. Reason for decision: Since p value < alpha, the decision is to reject the Null hypothesis
iv. Conclusion: at 5% level of significance, the sample data do not show sufficient evidence
that the average percentage of obsese children in the US is 32%
i. Construct a 95% Confidence Interval for the true mean or proportion. Include a sketch of
the graph of the situation. Label the point estimate and the lower and upper bounds of the
Using the T interval to find 95% confidence interval for x bar = 14.29, s=-.032102, n =51,
we get ( 14.281, 14.299)
7 0 16
11 4 14
17 9 12
21 5 10
27 0 8
31 0 6
5 7 9 11 13 15 17 19 21 23 25 27
Percentage of obese children across different states
27 29 31 33 35 More
cross different states
District of Obese Children
Alabama 16.70% 3
Alaska 11.10% 14
Arizona 12.20% 40
Arkansas 16.40% 9
California 13.20% 41
Colorado 9.90% 51
Connecticut 12.30% 49
D.C. 14.80% 43
Delaware 22.80% 22
Florida 14.40% 39
Georgia 16.40% 12 Average 14.29%
Hawaii 13.30% 50 s 0.032102
Idaho 10.10% 31
Illinois 15.80% 26
Indiana 15.60% 11
Iowa 12.50% 19
Kansas 14.00% 23
Kentucky 20.60% 7
Louisiana 17.20% 4
Maine 12.70% 34
Maryland 13.30% 28
s 13.60% 48
Michigan 14.50% 10
Minnesota 10.10% 30
Mississippi 17.80% 1
Missouri 15.60% 13
Montana 11.10% 45
Nebraska 11.90% 18
Nevada 12.40% 36
Hampshire 12.90% 35
New Jersey 13.70% 42
New Mexico 16.80% 38
New York 15.30% 37
North Carolina 19.30% 16
North Dakota 12.10% 21
Ohio 14.20% 17
Oklahoma 15.40% 8
Oregon 14.10% 29
Pennsylvania 13.30% 24
Rhode Island 11.90% 46
South Carolina 18.90% 5
South Dakota 12.10% 20
Tennessee 20.00% 6
Texas 19.10% 15
Utah 8.50% 44
Vermont 11.30% 47
Virginia 13.80% 27
Washington 10.80% 32
West Virginia 20.90% 2
Wisconsin 13.50% 25
Wyoming 8.70% 33