Discrete Random Variables

As discussed in the previous section, a normal distribution has particular characteristics it conforms to. i.e.

Standard Deviation of Mean= 0.4762Standard Deviation of Median= 0.7539The standard deviation of the Mean is smaller, which means all of the data points will tend to be very close to the Mean. The Median with a larger Standard Deviation will tend to have data points spread out over a large range of values. Since the Mean has the smaller value of the Standard Deviations, it has the least variability.

and SD are _______________________ statistics. The mean is the measure of Central tendency of a distribution while SD is a measure of dispersion of its scores. Both X and SD is descriptive statistics.

If the population was distributed normally the sample size to be taken will decrease. As the population normally distributes the variance and standard deviation population means will decrease so less number of sample would be appropriate to give good estimates of disease severity to determine the disease epidemics.

Experimental research concentrates on how and why something happens. It is the evaluation of how an independent variable (a manipulated factor) affects a dependent variable (an observed factor). The outcome can be affected by a number of elements; obtaining random and representative samples of the study population, experimenter bias and extraneous variables.

6. When do the mean and median have the same value? 7. Describe the relationship between variance and standard deviation.

8. Analyze: How does the standard deviation relate to the consistency and range of a data set?

Ans: the random variable is being used in statistics and probability most of the time. This is also called stochastic or aleatory variable as his has an ability of making its values vary according to the subject or according to the chance that occur. A random variable has the ability of taking a set of different kind of values that also have the different value with the value associated with it.

-The shape of both data sets fall within the rule of thumb estimate and that actual standard deviation. There is a much high range for both and that is because there are several data samples that fall outside of the standard deviation.

Statistics uses math to determine whether or not an experiment happened by chance. In other words, it determines the probability of your results being by chance or if it is factual data. The mathematical ways of determining probably include looking at mean, standard deviation, mode, and median. This experiment will use statistics to test the probability.

Statistical dispersion is measured by a number system. The measure would be zero, if all the data were the same. As the data varies, the measurement number increases. There are two purposes to organizing this data. The first is to show how different units seem similar, by choosing the proper statistic, or measurement. This is called central tendency. The second is to choose another statistic that shows how they differ. This is known as statistical variability. The most commonly used statistics are the mean (average), median (middle or half), and mode (most frequent data). After the data is collected, classified, summarized, and presented, then it is possible to move on to inferential statistics if there is enough data to draw a conclusion.

-When you have large sample sizes the effects of the extreme values on the sample mean downsize the larger the sample sizes are. When you have a large sample, even if the population isn’t distributed normally the sampling distributed of the mean will be very close to normally distributed.

What type of experiment involves manipulating the independent variable and measuring the dependent variable in a natural setting? B. field experiments.

(ii) Experimental vs Non-experimental Research: Experimental research examine the possible influence that one factor or condition may have on another factor or condition. The experimental research is mostly conducted in laboratory, as it is in physics, biology and other pure sciences.

b. What is the probability of failing on the first 2 trials and passing on the third? c. What is the probability of failing on all 3 attempts? 9.