Shortcut Methods

JEE Main

Mean, Median, Mode, and Range

  • Mean (Average): Sum of all values divided by the number of values.
  • Median: Middle value when the data is arranged in ascending order.
  • Mode: Value that appears most frequently.
  • Range: Difference between the highest and lowest values.

Probability of an Event

  • Ratio of the number of favorable outcomes to the total number of possible outcomes.
  • Can be expressed as a fraction, decimal, or percentage.

Conditional Probability

  • Probability of an event occurring given that another event has already occurred.
  • Written as P(A | B), where A is the event of interest and B is the condition.

Bayes’ Theorem

  • Used to calculate the probability of an event occurring based on prior knowledge and conditional probabilities.
  • P(A | B) = (P(B | A) * P(A)) / P(B)
  • P(B | A) = conditional probability of event B occurring given that event A has occurred
  • P(A) = probability of event A occurring
  • P(B) = probability of event B occurring

Binomial Distribution

  • Discrete probability distribution of the number of successes in a sequence of independent yes/no experiments, each of which yields success with probability p.
  • P(X = x) = (nCx) * p^x * q^(n-x)
  • nCx = n! / (x!(n-x)!)
  • p = probability of success
  • q = probability of failure = 1 - p
  • n = number of independent experiments

Normal Distribution

  • Also known as the Gaussian distribution or bell curve.
  • A continuous probability distribution that is symmetric around the mean with a bell-shaped curve.
  • Completely determined by its mean and standard deviation.

Standard Deviation and Variance

  • Standard deviation (σ): Square root of the variance.
  • Variance (σ^2): Average of the squared differences between each value in the data set and the mean.
  • Measures the spread or dispersion of data.
  • A low standard deviation indicates that the data is clustered close to the mean, while a high standard deviation indicates that the data is spread out.

Correlation and Regression

  • Correlation: Measures the strength and direction of a linear relationship between two variables.
  • Linear regression: Models the relationship between a dependent variable and one or more independent variables using a linear equation.

CBSE Class 11-12

Mean, Median, Mode, and Range

  • Same as JEE Main.

Probability of an Event

  • Same as JEE Main.

Conditional Probability

  • Same as JEE Main.

Binomial Distribution

  • Same as JEE Main.

Normal Distribution

  • Same as JEE Main.

Standard Deviation and Variance

  • Same as JEE Main.

Correlation and Regression

  • Same as JEE Main.

Frequency Distributions

  • Tally marks or a table to organize data into intervals and record the frequency of each interval.

Cumulative Frequency Distributions

  • Sum the frequencies of all intervals up to and including a given interval.

Histograms

  • Graphical representation of a frequency distribution using bars.

Measures of Central Tendency

  • Mean: Average value.
  • Median: Middle value when the data is arranged in ascending order.
  • Mode: Value that appears most frequently.

Measures of Dispersion

  • Range: Difference between the highest and lowest values.
  • Standard deviation: Square root of the variance.
  • Variance: Average of the squared differences between each value in the data set and the mean.

Skewness and Kurtosis

  • Skewness: Measures the asymmetry of a data distribution.
  • Kurtosis: Measures the peakedness or flatness of a data distribution.

Sampling Techniques

  • Techniques used to select a sample from a population to represent the entire population.
  • Simple random sampling: Each individual in the population has an equal chance of being selected.
  • Stratified sampling: Population is divided into strata, and a sample is taken from each stratum.
  • Cluster sampling: Population is divided into clusters, and a sample of clusters is taken.

Hypothesis Testing

  • Statistical method used to determine whether a hypothesis is supported or refuted based on sample data.
  • Null hypothesis (H₀): Statement being tested.
  • Alternative hypothesis (H₁): Statement that contradicts the null hypothesis.
  • P-value: Probability of obtaining a test statistic as extreme as or more extreme than the observed test statistic, assuming the null hypothesis is true.
  • Significance level (α): Maximum p-value at which the null hypothesis can be rejected.

Linear Regression

  • Used to model the relationship between a dependent variable and one or more independent variables using a linear equation.
  • Equation: y = mx + b
  • y: dependent variable
  • x: independent variable
  • m: slope
  • b: y-intercept