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