MATH1280 Statistics 1 Learning journal UNIT6
Grades 10/0-10
1. Learning Journal Reflective Comments:
Write short reflective comments or notes about your learning activities during the week. It is highly recommended that you make these entries on a daily basis. You will be assessed on the completeness of your Learning Journal, and the quality of your self-reflection.
You should date each entry, and use clear titles and sub-headings. These entries should be brief, direct sentences indicating quick comments or notes such as:
* when you completed each step in the Learning Guide during the week,
* any problems or unexpected events that occurred during the week (including
problems understanding new or old material), and
* any other noteworthy that might affect your performance in this class.
There is no need to include personal information or details of family events, but be sure to mention the existence of any situations that will positively or negatively affect your ability to focus on the classwork.
2. Vocabulary and R functions (be sure to include an APA citation)
a) What is a normal distribution? _________________
b) What does the pnorm() function do?_________________________
3. Task
If you know the mean and standard deviation of a normally distributed population, and somebody asks you questions about the highest 1% and lowest 1% of numbers in that population, what could you tell them? Pick your own values for the mean and standard deviation and then answer the question for those values. Choose one of these R functions to answer the question: dnorm(), pnorm(), qnorm(), rnorm().
_______________________________________________________________________________________________
1. Learning Journal Reflective Comments:
7/24 Reading learning guides and the textbook
7/25 Reading the textbook again, and using the R program
7/26 Discussion Forum and Written assignment
7/27 Attempt self-quiz of unit1 to 6 again and again, and attempt Graded quiz
7/28 Learning Journal
2. Vocabulary and R functions (be sure to include an APA citation)
a) What is a normal distribution? _________________
The normal distribution is a tool used primarily to understand the distribution of factors within a population and to identify causes and probabilities (Yakir, 2011). The most fundamental property of the normal distribution is that the mean, mode, and median match.
b) What does the pnorm() function do?_________________________
The pnorm() function calculates probability and cumulate distribution.
3. Task
If you know the mean and standard deviation of a normally distributed population, and somebody asks you questions about the highest 1% and lowest 1% of numbers in that population, what could you tell them? Pick your own values for the mean and standard deviation and then answer the question for those values. Choose one of these R functions to answer the question: dnorm(), pnorm(), qnorm(), rnorm().
The lowest 1% of the population can be said 0.01, and the highest 1% can be said 0.99. When use qnorm(), the lowest 1% is qnorm (0.01, mean=, sd=), and the highest 1% is qnorm(0.99,mean=,sd=).
For example, when supposing that the lowest 1% will have a mean of 100 and set the standard deviation as 15, it must be as below.
The lowest 1% is
> qnorm(0.01,mean=100,sd=15)
[1] 65.10478
And the highest 1% is
> qnorm(0.99,mean=100,sd=15)
[1] 134.8952
Another example, X follows normal with mean of height of Japanese women of 158cm and set standard deviation of 10cm. When answering this question using qnorm() will be as below.
The lowest 1%
> qnorm(0.01,mean=158,sd=10)
[1] 134.7365
The highest 1%
> qnorm(0.99,mean=158,sd=10)
[1] 181.2635
References
Yakir. B, (2011). Introduction to Statistical Thinking (With R, Without Calculus). Retrieved from https://my.uopeople.edu/pluginfile.php/1097279/mod_book/chapter/267923/MATH1280RInstall Notes. pdf
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