Inferential Statistics Report
Generated Mar 30, 2019 by staceyxfaye
I: Introduction
My group and I designed a survey to assess and learn about the health rating and habits of our friends, families and acquaintances. The population that we sampled was adults, 25-45 and non-military status. The information was collected from Facebook friends so the sample is not random. It is a convenience sample with a voluntary response.
The survey contained the following questions:
1: How many days in a week do you do at least 20 minutes of moderate physical activity (an activity that increases heart rate, increases respiration/breathing rate, increases sweating and/or causes muscle fatigue)?
2: How many hours in a day do you spend sedentary/sitting (ex: eating, commuting, working, watching tv, etc)?
3: Are you male or female?
4: How would you rate your overall health: Poor, Good, Very Good, Excellent
II: Looking at a Categorical-Variable
a) The pie chart displays the results to the question “Are you male or female”
b) <result1>
c) From the pie chart, we were able to conclude that 104 (63.03%) of the participants were female and 61 (36.97%) of them were male out of 165 total participants.
d) One sample proportion summary confidence interval:
p : Proportion of successes
Method: Standard-Wald
95% confidence interval results:
Proportion |
Count |
Total |
Sample Prop. |
Std. Err. |
L. Limit |
U. Limit |
p |
104 |
165 |
0.63030303 |
0.037579904 |
0.55664777 |
0.70395829 |
e) Confidence interval=[0.55664777,0.70395829]
f) There is a 95% chance that the confidence interval contains the true population mean. 104 of the 165 participants were female which gives us a confidence level that 95% of likely participants in this type of survey would be female.
g) Margin of error: 0.07365526
III: Looking at a Numerical Variable
This is the Histogram of responses to the question “How many days in a week do you do at least 20 minutes of moderate physical activity (an activity that increases heart rate, increases respiration/breathing rate, increases sweating and/or causes muscle fatigue)?”
a) <result2>
b) Summary statistics:
Column |
n |
Mean |
Variance |
Std. dev. |
Std. err. |
Median |
Range |
Min |
Max |
Q1 |
Q3 |
Days/Week with Moderate Activity |
165 |
4.1575758 |
4.1091648 |
2.0271075 |
0.1578101 |
4 |
7 |
0 |
7 |
3 |
6 |
One sample T confidence interval:
μ : Mean of variable
95% confidence interval results:
Variable |
Sample Mean |
Std. Err. |
DF |
L. Limit |
U. Limit |
Days/Week with Moderate Activity |
4.1575758 |
0.1578101 |
164 |
3.8459742 |
4.4691773 |
Confidence interval: [3.8459742,4.4691773]
Margin of error: 0.31160155
A T interval was used because the population standard deviation is unknown and the sample size is greater than 30. With this confidence interval, I am 95% confident that the participants of this survey participate in 20 minutes of moderate activity between 3 and 4 days per week.