Estimation Theory MBA 1st Year Semester Short Question Answer Notes 3 Mock Papers For Self-Assessment Unit-Wise Division Of The Content Knowledge Boosters To Illuminate The Learning Solved Case Studies For Practice Theory Of Estimation, Point Estimation, Interval Estimation. Hypothesis Testing Null And Altenative Hypothesis; Type I And Type Errors; Testing Of Hypothesis; Large Sample Test, Small Sample Test, (T,F,Z Test And Chi-Square Test) Notes.
SHORT ANSWER QUESTIONS
Estimation Theory MBA 1st Year Semester Short Question Answer Notes | Index
Estimation Theory MBA 1st Year Semester Short Question Answer Notes Page.1
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Q.1. Distinguish between sample and population.
Ans. In every branch of science, there is lack of resources to study more than a fragment of the phenomena that might advance our knowledge. In this, fragment is termed as sample and phenomena is termed as sample and phenomena that might advance our knowledge. In this, fragment is termed as sample and phenomena is termed as the opulation. Sample aims to obtain information about population under course of study.
Sample is a portion of the population which is examined to estimate the characteristics of the population. The selected portion of any consignment is called as a sample.
The population represents the entire group of units that is the focus of the study. It consists of all the persons in the country or those in a particular geographical location or economic group depending on the purpose and coverage of the study. It is a set of study concerning which statistical inferences are to be drawn based on a random sample that is taken from the population.
It is an aggregate of measurable quantities or a set of numbers.
Q.2. Write a short note on estimation theory.
Ans. Estimation Theory: It refers to the technique and method by which population parameters are estimated from sample studies. It is essential when a sample study has been conducted.
When one makes an estimate of a population parameter, a sample statistic is used. This sample statistic is an estimator, i.e. a random variable.
Estimation theory was developed by Prof. R.A. Fisher in 1930 and has been grouped in two classes:
1. Point Estimation: It is a specific value of a sample statistic that is used to estimate a population parameter. This estimation deals with the task of selecting a specific sample value as an estimate for a population parameter.
For a statistical point estimate, the sampling distribution of the estimator provides information about the best estimator. The notations used in point estimation are:
0 = Population parameter of interest being estimated.
0 = Point estimator of e.
2 Interval Estimation: It establishes an interval consisting of a lower limit and an upper limit in which the true value of the population parameter is expected to fall. This interval is confidence interval. It is a particular kind of interval estimate of a population parameter. It is used to indicate the reliability of an estimate An interval estimate of a population mean can be developed either by the population standard deviation ‘o’ or the sample standard deviation to compute margin of error.
Q.3. Define null hypothesis, critical region and two sided test used in testing of statistical hypothical hypothesis.
Or Explain the term ‘Null hypothesis’.
Ans. Null Hypothesis: A statistical hypothesis which is stated for the purpose of acceptance is called null hypothesis. It is usually denoted by the symbol H,, the null hypothesis expressed symbolically as:
Hou = 162 cms
‘Null hypothesis is the hypothesis which is tested for possible rejection under the assumption it is true.’
The following may be borne in mind in setting the null hypothesis:
1. If we want to test the significance of the difference between a statistic and the parameter or between two sample statistics then we set-up a null hypothesis that’s the difference is significant. This means that the difference is just due to fluctuation of sampling.
2. If we want to test any statement about the population, we set-up the null hypothesis that it is true. For example, if we want to find the population mean which has
specified valueu0, then we set-up the null hypothesis.
Critical Region: It is a rejection region which is associated with a statistical test in a subset of the sample space such that one reject the null hypothesis in favour of the alternative if and only if the sample proved wrong by the that is observed falls within this set.
In concurrent programming, a critical region is piece of code that accesses a shared resource that must not be concurrently accessed by more than one thread of execution. It will terminate in fixed time and a thread, task or process will have to wait a fixed time to enter it.
Two Sided Testing: It is a hypothesis test that looks for both sides-either increase or decrease in the parameter. This change in test is used to test the null hypothesis that predicts the direction of null hypothesis.
Q.4. What are the steps in the test of significance problem?(2005-06)
Ans. As distinguished from variable where quantitative measurement of a phenomenon is possible in case of attributes, we can only find out presence or absence of a particular characteristic samples from a population whose members possess the attribute. For example, in the study of attribute literacy, a sample may be taken and people are classified as literates and illiterates. Thus, out of 1,000 people selected for the sample, 100 are found literates and 900 illiterates.
Steps involved in the test of significance problem:
1. Set-up the null hypothesis Ho.
2. Set-up the alternative hypothesis. If His two tailed, use two tailed test and if H, is right tailed,
then use right tailed test.
3. Choose the appropriate level of significance(a). This is to be decided before sample is drawn.
4. Choose the test statistic.
Tests for number of successes, the sampling distribution of the number of successes follows a inomial probability distribution.
S.E. number of successes = Inpq