Sample Mean, Variance and Descriptive Estimation Previous Year Questions (PYQs) for GATE DA: 2+ Solved Questions with Step-by-Step Solutions

    Solve 2+ Sample Mean, Variance and Descriptive Estimation previous year questions for GATE DA with answers and detailed solutions. Free sample questions below.

    Chapter Roadmap: Statistical Inference

    Chapter Journey: Statistical Inference

    1
    Descriptive Foundations (Current Topic)
    Sample Mean Updates & Variance Identities. Efficient calculation of basic statistics.
    2
    Point Estimation
    Method of Moments, MLE, Unbiasedness, Consistency.
    3
    Interval Estimation
    Confidence Intervals for Mean and Proportions.
    4
    Hypothesis Testing
    Null vs Alternative, Errors, Z/T/Chi-square tests, P-values.
    Exam Weightage Hint: Hypothesis Testing and MLE are the highest yield areas. However, the identities in this first topic are often the hidden step required to solve complex numerical questions quickly.

    Concept: The Running Mean Update

    The Running Mean Update

    Standard definition of sample mean for observations:

    If a new observation arrives, recalculating from scratch requires summing terms. For large or streaming data, this is costly.

    The Update Formula

    1 Total sum of first items:
    2 New total sum:
    3 New mean:
    + New Data Point → Instant Update

    Sample Mean, Variance and Descriptive Estimation: Solved Questions with Step-by-Step Explanations (2 Problems)

    Question 1 · Probability and Statistics NAT
    For a given data set , where , it is known that



    Let us denote

    The value of



    is __________ . (Answer in integer)
    Question 2 · Probability and Statistics NAT
    The sample average of 50 data points is 40. The updated sample average after
    including a new data point taking the value of 142 is ______.

    More previous year questions (pyqs) in this unit

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    Sample Mean, Variance and Descriptive Estimation Previous Year Questions (PYQs) for GATE DA: 2+ Solved Questions with Step-by-Step Solutions

    Solve 2+ Sample Mean, Variance and Descriptive Estimation previous year questions for GATE DA with answers and detailed solutions. Free sample questions below

    A question from this chapter

    Question 1
    For a given data set , where , it is known that



    Let us denote

    The value of



    is __________ . (Answer in integer)
    Question 2
    The sample average of 50 data points is 40. The updated sample average after
    including a new data point taking the value of 142 is ______.
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