Competitive Exams: Statistics Glossary L to P

Statistics Glossary: L to P

  • Large sample: A sample whose size is above 30.
  • Least squares: Any line or curve fitting model, that minimizes the squared distance of the data points to the line.
  • Leptokurtic: If the curve is more peaked than the normal curve it is called Leptokurtic.
  • Lower Quartile (Q1): It is the size of the 25th observation when the data is arranged in ascending or descending order or the 25th percentile of a set of measures.
  • Lines of Regression: In the scatter plot, if the variables are highly correlated then the dots lie in a narrow strip. If the strip is nearly a straight line then it is called a line of regression.
  • Level of Significance: The probability level below which we reject the hypothesis.
  • Mean: It is the some of the measures in a distribution by their number.
  • Mathematical Expectations: The sum of the products of values of a variable and their respective probabilities
  • Measures of Central Tendency: The descriptive measures which indicate the centered values of a set of observations.
  • Measure of variation: It is the descriptive measures which points out the spread of values in a set of values.
  • Median (Q2): The value or the size of the central item of the arranged data or the middle i.e.. 50th percentile of the ordered distribution.
  • Mode: It is the size of the item which occurs most frequently in a distribution.
  • Mutually Exclusive: Outcomes such that the occurrence of one preclude the occurrence of the other.
  • Moments: The arithmetic mean of the various powers of the deviations in any distribution.
  • Negative Relationship: In a relationship between two variables when one increases the other decreases or vice-versa.
  • Nominal: A scale using numbers, symbols, or titles to designate the different sub-class.
  • Normal Distribution: It is the limiting form of the binomial distribution when the number of trials is very large and the probability of success and failure is very small.
  • Non-parametric Test: Statistical test used, when the population cannot be assume to be normal or when the level of measurements is ordinal or less.
  • Null-Hypothesis: The opposite or reverse of the researcher's hypothesis.
  • Ogive: A graphic representation, that displays a running total.
  • One-Tail Test (One sided Test): A test that predicts that one value is higher than the other.
  • Ordinal: It is a scale which uses numbers or symbols to rank the intervals are unspecified.
  • Out-lier: The points of the data, that fall far away from most of the other points of the data.
  • Parameter: A characteristic of population.
  • Percentile: It is a value in an order set of measurement, that is calculated on the basis of percentage.
  • Pie-chart: It is a circular diagram which is a circle (pie) divided by radii (like slices of a cake or pie)
  • Platy kurtic: If the curve is flat-topped when compared to the normal curve then it is a platy kurtic curve.
  • Point Estimate: A number computed from a sample, representing a population parameter.
  • Population: A group of phenomena having something in common.
  • Positive Correlation: A relationship between two variables such that when one increases the other also increases or when one decreases the other also decreases.
  • Power: When a hypothesis is fall, the probability that a test will reject the null hypothesis is called Power.
  • Probability: A quantity measure of the chances of an outcome or outcomes of a random experiment.
  • Probability-Distribution: An unbroken (smooth) curve which indicates the frequency distribution of a continuous random variable.