# summery of STAT - SUMMARY STAT 101 Descriptive statistics 1...

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SUMMARY STAT 101Descriptive statistics1. A sample is a subset of the people or objects in a population.2. Frequency distributions are not a subset of inferential statistics. 3. Data which have already been collected by someone are called Secondary data4. The Population is a collection of all individuals, objects, or measurements ofinterest.5. A numerical summary of a population is a parameter.6. A sample value that lies very far away from the majority of the other samplevalues is an outlier.7. Descriptive statistics are used to help us to compare the sample to the wholepopulation.8. Descriptive statistics utilize numerical data to make estimates, decision,prediction or other generalizations about a larger set of data.9. A point estimate is a statistic that estimates a population parameter.10. A statistical measure based upon the entire population is called parameter whilemeasure based upon a sample is known as Statistic.11. Hypothesis testing and estimation are not both types of descriptive statistics. 12. The weight of your car and its gas mileage are likely to be dependent events.13. The class frequency is not the difference between consecutive lower classlimits. 14. The relative frequency of a class is computed by dividing the frequency of theclass by the sample size15. The color of the player t-shirt is qualitative data.Measures of variation1. Skewed distributions usually does not show the familiar bell shape.2. If right tail is longer than left tail then distribution is called Positively Skewed3. Standard deviation is the square root of variance.4. You can claim that there is a significant difference between scores from twogroups if the difference between the means is large compared to the standarderror. 5. If x is 4 and the distribution is 2, 3, 4, 5, 6, the sum of squared deviations fromthe x will be 10.
6. Variance and standard deviation are the most stable and are foundations for moreadvanced statistical analysis.7. Range is not a common measure of central tendency. 8. In a class of 100, the mean on a certain exam was 50, the standard deviation, 0.This means everyone had a score of exactly 50.9. If a distribution is skewed to the left, then it is Negatively skewed.10. Median is not a measure of variability. 11. The standard deviation is equal to square root of the Variance.12. If the sum of squares of nine sample values isx2=¿45.5 and their sum isx=¿17.5, then the variance of these values is 1.43.Measures of central tendency1. If a distribution is positively skewed, the median will not be smaller than themode.2. The mode is the value that occurs most often in a sample of data.3. Arithmetic mean is influenced by the extreme values in the distribution.4.Themeanandmedianforthefollowingdataset.7,8,10,9,7,6,7,14,16,5,8,5,16,7,10 is mean is 7, median is 7.
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