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statistic.Question: What is the difference between cumulative frequency distribution andCumulative Frequency Polygon?.Answer: There is no difference between cumulative frequency distribution &Cumulative Frequency Polygon,because the graph of cummulativefrequency distrbution is known as Cumulative Frequency Polygon/ogive.Question: What is Frequency? What are the steps for making frequencydistribution?Answer:^ Frequency: It is a record of how often each value (or set of values) of the variable inquestion occurs. It may be enhanced by the addition of percentages that fall intoeach category Steps in Frequency Distribution: Following are the basic rules to construct frequency distribution:1. Decide the number of classes into which the data are to be grouped& it depends upon the size of data.2. Determine the RANGE (difference between the smallest &largestvalues in data) data.3. Decide where to locate the class limit (numbers typically use to
identify the classes).4. Determine the reaming class limits by adding the class intervalrepeatedly.5. Distribute the data into classes by using tally marks and sum it infrequency column. Finally, total the frequency column to see that all data havebeen accounted for.Question: What is Box & Whisker Plot?Answer:^ Box and Whisker Plot (or Box plot): A box and whisker plot is a way of summarizing a set of data measuredon an interval scale. It is often used in exploratory data analysis. It is a type ofgraph which is used to show the shape of the distribution, its central value, andvariability. The picture produced consists of the most extreme values in the dataset (maximum and minimum values), the lower and upper quartiles, and themedian.A box plot (as it is often called) is especially helpful for indicating whether adistribution is skewed and whether there are any unusual observations (outliers)in the data set.Box and whisker plots are also very useful when large numbers of observationsare involved and when two or more data sets are being compared.Question: What is Mean, Median & Mode?Answer:^ Mean:
same average e.g.Data 1:5, 5,5,5,5 having mean=5Data 2:1, 5,6,6,7 having mean=5Hence in such a situation we, need a measure which tell us howdispersed the data are. The measure used for this purpose is calledmeasure of dispersion. Question: What is the relation between these two Moments & Moment Ratios. ?Answer: Moments: A moment designates the power to which deviations are raisedbefore averaging them. Moment ratio: These are certain ratios in whichboth numerators and the denominators are moments.Question: What is the difference between frequency and frequency distribution.?Answer: Frequency:The number of observations falling in a particular class isknown as class frequency or simply frequency.Frequency distribution.When we arrange the frequencies in a form of table then it isknown as Frequency distribution.Question: What is meant by standard deviation?.Answer: Standard deviation tells how tightly a set of values is clustered around theaverage of those same values.Question: What is the difference between these two limits when we are dealing with
continuous random variable: 0<5 and 0
≤^ x^ ≤. Answer: In case ofcontinuous random variable there is no differecce both arediscribing the same thing either we mention the equal sign or not that is,the random variable ranging from 0 to 5.Question: What is the difference between the Poisson distribution and the normaldistribution?Answer: Poisson distribution. The Poisson distribution is referred to as thedistribution of rare events. Examples of Poisson distributed variables arenumber of accidents per person, number of sweepstakes won per person,or the number of catastrophic defects found in a production process.While: Normal Distribution. The normal distribution (the "bell-shapedcurve" which is symmetrical about the mean) is a theoretical functioncommonly used in inferential statistics as an approximation to samplingdistributions. In general, the normal distribution provides a good modelfor a random variable, when: There is a strong tendency for the variableto take a central value; Positive and negative deviations from this centralvalue are equally likely; The frequency of deviations falls off rapidly asthe deviations become larger.Question: What is the difference between type-I error and type -II error ?.
