Statistics II (BSc CSIT, STA210): the questions likely to come
32 analyzed questions from 8 past papers (2074-2082), grouped by syllabus unit — each with its probability, how often it's been asked, and where to study the answer.
Define a probability distribution. Explain the binomial distribution with its mean and variance, and state the conditions under which it is applied.
Probability Distribution
A probability distribution is a mathematical function (or table) that assigns to each possible value of a random variable the probability of its occurrence. For a discrete random variable taking values it is described by the probability mass function with and ; for a continuous variable it is described by a probability density function with and .
Binomial Distribution
A discrete random variable follows a binomial distribution if it counts the number of successes in independent Bernoulli trials, each having success probability (and failure ). Its probability mass function is
Mean and Variance
Since , the variance is always less than the mean , i.e. for the binomial distribution mean variance.
Outline of the mean: writing where each is Bernoulli with , by linearity ; similarly and by independence .
Conditions for Application
The binomial distribution applies when:
- The number of trials is fixed and finite.
- Each trial has only two outcomes — success or failure (dichotomous).
- The trials are independent of one another.
- The probability of success remains constant from trial to trial.
Examples: number of heads in 10 tosses of a coin, number of defective items in a sample of fixed size, number of correct answers in a multiple-choice test.
Probability and Probability Distributions
Define a probability distribution. Explain the binomial distribution with its mean and variance, and state the conditions under which it is applied.
Define index numbers and explain Laspeyres' and Paasche's price index methods.
State and explain the addition and multiplication theorems of probability with examples.
Explain the Poisson distribution with its mean and variance and state its applications.
Define a random variable. Differentiate between discrete and continuous random variables with examples.
Explain the normal distribution and its properties. The mean of a normal distribution is 50 and standard deviation is 10; find the probability that a value lies between 45 and 62.
Define mathematical expectation. State and prove its properties.
Define stochastic process. In a town each day is either sunny or rainy. A sunny day is followed by another sunny day with probability 0.8, whereas a rainy is followed by sunny day is with probability 0.4. If it rains on Sunday, make forecast for Monday and Tuesday.
Sit a probable paper
A full mock exam built from the most likely questions, mirroring the real paper's structure. Every slot is a real past question.
Most Probable Paper
Mirrors the real structure · 60 marks · based on 8 past papers
- 1.[10 marks]
What is hypothesis testing? Explain the procedure of testing of hypothesis including null and alternative hypotheses, level of significance, types of errors and the critical region.
This question has recurred in 4 of 8 years; so far only in internal assessments, not the board; and its topic (Testing of Hypothesis) appears in 100% of years.
- 2.[10 marks]
What is sampling? Explain different methods of probability and non-probability sampling with their merits and demerits.
This question has recurred in 4 of 8 years; so far only in internal assessments, not the board; and its topic (Sampling and Sampling Distributions) appears in 88% of years.
- 3.[10 marks]
Define a probability distribution. Explain the binomial distribution with its mean and variance, and state the conditions under which it is applied.
This question has recurred in 3 of 8 years; so far only in internal assessments, not the board; and its topic (Probability and Probability Distributions) appears in 100% of years.
- 1.[5 marks]
Define Karl Pearson's coefficient of correlation and state its properties.
This question has recurred in 6 of 8 years; so far only in internal assessments, not the board; and its topic (Correlation and Regression) appears in 88% of years.
- 2.[5 marks]
What are regression coefficients? State their properties.
This question has recurred in 6 of 8 years; so far only in internal assessments, not the board; and its topic (Correlation and Regression) appears in 88% of years.
- 3.[5 marks]
Explain the concept of sampling distribution and standard error.
This question has recurred in 6 of 8 years; so far only in internal assessments, not the board; and its topic (Sampling and Sampling Distributions) appears in 88% of years.
- 4.[5 marks]
Define index numbers and explain Laspeyres' and Paasche's price index methods.
This question has recurred in 5 of 8 years; so far only in internal assessments, not the board; and its topic (Probability and Probability Distributions) appears in 100% of years.
- 5.[5 marks]
State and explain the addition and multiplication theorems of probability with examples.
This question has recurred in 5 of 8 years; so far only in internal assessments, not the board; and its topic (Probability and Probability Distributions) appears in 100% of years.
- 6.[5 marks]
Explain the Poisson distribution with its mean and variance and state its applications.
This question has recurred in 5 of 8 years; so far only in internal assessments, not the board; and its topic (Probability and Probability Distributions) appears in 100% of years.
- 7.[5 marks]
Define a random variable. Differentiate between discrete and continuous random variables with examples.
This question has recurred in 5 of 8 years; so far only in internal assessments, not the board; and its topic (Probability and Probability Distributions) appears in 100% of years.
- 8.[5 marks]
Define mathematical expectation. State and prove its properties.
This question has recurred in 5 of 8 years; so far only in internal assessments, not the board; and its topic (Probability and Probability Distributions) appears in 100% of years.
- 9.[5 marks]
Explain the F-test for the equality of two population variances.
This question has recurred in 5 of 8 years; so far only in internal assessments, not the board; and its topic (Testing of Hypothesis) appears in 100% of years.
Behind the numbers
The raw evidence the predictions are computed from: marks per unit per year, syllabus weights, trends, and coverage.
Show the heatmap, topic table and coverage analysis
The receipt: marks per unit, per year
Each row is a syllabus unit, each column an exam year, each cell the marks that unit earned that year. Click any cell to see the actual questions behind it.
| # | Syllabus unit | Probability | Appeared | Avg marks | Syllabus weight | Exam vs syllabus | Trend | Questions |
|---|---|---|---|---|---|---|---|---|
| 1 | U1Probability and Probability Distributions | Very likely100% | 22.5 | 22%10 lecture hrs | Over-examinedexam 30% · syllabus 22% | Fading | 7 recurring8 total | |
| 2 | U4Testing of Hypothesis | Very likely100% | 22.5 | 27%12 lecture hrs | Balancedexam 30% · syllabus 27% | Steady | 5 recurring12 total | |
| 3 | U5Correlation and Regression | Very likely88% | 12.9 | 11%5 lecture hrs | Balancedexam 15% · syllabus 11% | Steady | 3 recurring4 total | |
| 4 | U2Sampling and Sampling Distributions | Very likely88% | 11.4 | 18%8 lecture hrs | Balancedexam 13% · syllabus 18% | Steady | 2 recurring4 total | |
| 5 | U3Estimation | Likely75% | 10 | 16%7 lecture hrs | Under-examinedexam 10% · syllabus 16% | Steady | 2 recurring3 total | |
| 6 | U6Non-Parametric Tests and Statistical Quality Control | Occasional12% | 10 | 7%3 lecture hrs | Balancedexam 2% · syllabus 7% | Rising | none repeat1 total |
Study smart, not hard
Drag the slider: studying the top 4 units in priority order covers ~88% of all observed marks.
- ~80% line
Lecture time vs exam marks
Where the exam pays more than the curriculum spends: ● lectures vs ● exam marks, as a share of the whole course. A long teal-leading bar = high-yield unit.