Neco Model Questions Vol1 2020 Mathematics Question 49

Practice objective / multiple choice question 49 from the 2020 Neco Model Questions Vol1 Mathematics examination.

Neco Model Questions Vol1 2020 Mathematics Objective / Multiple Choice Hard Difficulty
Question 49 NECO_MODEL_QUESTIONS_VOL1 • 2020 • MATHEMATICS • objective

Class A has 20 students with mean score \(68\) and standard deviation \(5\). Class B has 30 students with mean score \(75\) and standard deviation \(8\). Assuming the two classes are combined, compute (a) the combined mean score and (b) the combined standard deviation of all 50 students (give the standard deviation to two decimal places).

Answer Options

A. Mean = 71.5, Standard deviation ≈ 7.50
B. Mean = 72.2, Standard deviation ≈ 6.85
C. Mean = 73.0, Standard deviation ≈ 8.10
Correct Answer D. Mean = 72.2, Standard deviation ≈ 7.72
Correct Answer
D
Correct Option:
Mean = 72.2, Standard deviation ≈ 7.72

About This Question

This is Neco Model Questions Vol1 2020 Mathematics Question 49. It is one of the objective questions from the 2020 Neco Model Questions Vol1 Mathematics examination.

Difficulty level: Hard .

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