Statistics and Research - Speech or Presentation Example

Statistics and Research Two major causes of problems faced when drawing conclusions about a population from a sample are: Lack of knowledge about the research topicSmall sample size 2. Descriptive Statistics is used to describe the quantitative results or summary for a given data set. On the other hand, inferential statistics is that which helps in drawing conclusions about a given data set. 3. Statistical significance implies how significantly probable are the conclusions being drawn, i.e., how high is the probability that the outcomes from a statistical test are unlikely to have occurred by chance.

Practical significance implies how far a certain outcome is significant in the practical sense, after the consideration of all the costs associated with its realization.4. William Edwards Deming was an American statistician who is mainly known for his works on industry quality control that could be used for enhancing industrial production. His suggestions on industrial quality control were that an organization can increase industrial production effectively and reduce costs efficiently by adopting proper management principles in their business strategy.

He developed a ratio that describes how the industrial quality control quotient can be increased, which is,Quality = (Total Work Efforts) / Total Costs of production.5. Reliability of data implies that the outcomes of the same tests being conducted on different samples of the same population would yield similar conclusions.6. External validity of the data implies how far the issue under study has really been addressed while conducting researches. Internal validity on the other hand could be found by judging a sub-sample out of the sample being considered to see if the conclusions drawn from it coincide with that of the larger sample.7. A statistic is the outcome of a test being conducted on a given sample.

A parameter on the other hand, is a variable that describes a certain characteristic of a given sample or a population.8. In this particular study, (a) the population comprises of all the U.S. residents aged 18 years and above, and (b) the sample is the 2100 people being chosen out of the lot.9. A range comprises of a lower and an upper limit within which a certain value is supposed to lie, with a high degree of probability.10. Frequency distributions determine the weights that must be assigned to a certain value which makes it a very important factor in statistics.11. The maximum value that relative frequency can take is 1.12. Relative frequency distribution is the proportion of times that a variable is taking a particular value in different trials.

On the other hand, the cumulative frequency is the additional frequency to the total frequency that a value assigns.13. 5 ways to graphically represent data are - (i) Scatter Diagram (ii) Line diagram (iii) Bar Diagram (iv) Pie Chart (v) Column Graph.14. Quantitative data implies that which could be quantitatively measured and qualitative data is the opposite of the former, e.g., logical results.15. An outlier is a data point that lies outside the average positions of its counterparts and so is often responsible for the occurrence of an outcome completely different from expected or reality.16. A stem and leaf plot is a way of graphically representing the data such that the underlying distribution becomes prominent from the arrangements of the values. 17. To report the performance of a standardized test, the various outcomes are categorized into a number of classes and then are ranked accordingly.18. C75 implies centile 75, meaning that the particular value lies 25% below the highest value.

Median = centile 50.19. (a) the mean is a parameter. (b) statistic. (c) statistic. (d) statistic.20. (a) continuous (b) discrete (c) discrete (d) continuous.21. (a) Ordinal. (b) Interval. (c) Nominal Scale. (d) Cardinal measure.22. Class Frequency61 – 63 264 – 66 167 – 69 070 – 72 673 – 75 076 – 78 079 – 81 782 – 84 085 – 87 788 – 90 0 91 – 92 123.

Numbers Rank 92 1 86 2 85 3 79 4 72 5 65 6 61 7