Project On Probability Modeling & Statistics.
Topic : Binomial Poisson and Normal.
Please mention The Measures of central tendency
The use of these distributions (in which cases these distributions are used) with illustrations.
Binomial approximation to the normal distribution.
What is Skewness and Kurtosis? How it is used and interpreted?
Binomial Distribution :
This kind of distribution is applied to single variable discrete data where results are the number of “successful outcomes” in a given scenario.
E.g. :
• no. of times the lights are red in 20 sets of traffic lights,
• No of students with green eyes in class of 40,
• No. of plants with diseased leaves from a sample of 50 plants.
Binomial distribution is used to calculate the
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Normal Distribution:
The normal distribution is a very common continuous probability distribution. Normal distribution is important in statistics and is often used in the natural and social sciences to represent real-valued random variables whose distributions are not known.
This distribution is useful because of the central limit theory. In its most general form, under some conditions which include finite variance), it states that average of random variables independently drawn from independent distributions converge in distribution to the normal, that is, become normally distributed when the number of random variables is sufficiently large.
The normal distribution is sometimes informally called the bell curve. However, many other distributors are bell-shaped( such as the Cauchy, students and logistic distribution).
Measure of Central Tendency :
The Mean, Median and Mode are all valid measures of central tendency, but under different conditions, some measures of central tendency become more appropriate to use than others.
Mean
The Mean is essentially a model of your data set. It is the value that is the most common. However, Mean is not often one of the actual values that you have observed in your data set, but it has one of its important properties is that it maximizes error in the prediction of any one value in your data set. That is, it is the value that produces the lowest amount of error
As discussed in the previous section, a normal distribution has particular characteristics it conforms to. i.e.
10. Identify whether these distributions are negatively skewed, positively skewed, or not skewed at all, and why.
Mean is the better estimate for the parameter of interest. The mean is more centered with least variability.
According to the website http://womenissues.about.com/cs/abortionstats/a/aaabortionstats.htm there are approximately 126,000 abortions conducted each day throughout the world. This website includes the abortion statistics of the world and breaks the data down to the demographics of the United States. It also discusses the decisions to have an abortion and the use of contraceptives in the United States. This was an informative website and included detailed statistics conducted by the Alan Guttmacher Institute. According to the website http://www.bls.gov/cps in 2000, gon average there were roughly 135 million employed and 6 million unemployed people in the labor force in the United States.h (p. 3) The websites definition of
Explain. I don’t think that mine has normal distribution. Mine has a wide range of numbers, but I don’t think that it is distributed like a normal graph should be distributed
Mean would be the most appropriate measure of central tendency to describe this data. This is because the mean is the average of all scores in the data set. If Dr. Williams were to graph the data into a bell shaped distribution, then the mean would be in the center where most of the scores are located. The mean is calculated using all information of the data set, and is the best score to use if you want to predict an individual score.
2. Based on the scale of measurement for each variable listed below, which measure of central tendency is most appropriate for describing the data?
It is one of the most popular and well known measures of central tendency. It can be used with both discrete and continuous data, although its use is most often with continuous data
The mean (x) is a measure of _central__________ __tendency___________ of a distribution while the SD is a measure of __dispersion___________ of its scores. Both x and SD are _descriptive___________ statistics.
Part 3: Based on what you’ve learned in this module about normal distributions, explain why a normal approximation of data would be helpful to view the data. For example, you could describe the steps that one would take to estimate the percentage of women with blood pressures in an age group.
What are the mean and standard deviation of the [pic] sampling distribution? Can we say that the shape of the distribution is approximately normal? Why or why not? (10 points)
The newest Boeing 787-9 Dreamliner is designed to be 206 feet in length. The manufacturing process for assembling the 787-9 follows a normal distribution with mean 205.8 feet and standard deviation 0.5 feet.
A pharmaceutical company is testing the effectiveness of a new drug for lowering cholesterol. As part of this trial, they wish to determine whether there is a difference between the effectiveness for women and for men. Using = .05, what is the value the test statistic?
-If both the items of interest and the items that are not of interest are least 5, the normal distribution can be used to approximate the binomial distribution.
5. The arithmetic mean is only measure of central tendency where the sum of the deviations of each value from the mean will always be zero