Waec Model Questions Vol1 2021 Mathematics Question 18

Practice objective / multiple choice question 18 from the 2021 Waec Model Questions Vol1 Mathematics examination.

Waec Model Questions Vol1 2021 Mathematics Objective / Multiple Choice Hard Difficulty
Question 18 WAEC_MODEL_QUESTIONS_VOL1 • 2021 • MATHEMATICS • objective

The following frequency distribution gives the scores of 38 students in a test. Score : 40 45 50 55 60 65 70 75 80 Frequency : 2 5 8 7 6 4 3 2 1 (a) Calculate the mean score (to 2 decimal places). (b) Calculate the standard deviation of the scores (population standard deviation, to 2 decimal places). (c) If one additional student scores 90, what will be the new mean (to 2 decimal places)?

Answer Options

A. Mean = 55.32, SD = 10.12, New mean = 56.78
B. Mean = 56.00, SD = 9.88, New mean = 57.00
C. Mean = 57.10, SD = 9.45, New mean = 58.02
Correct Answer D. Mean = 56.58, SD = 9.88, New mean = 57.44
Correct Answer
D
Correct Option:
Mean = 56.58, SD = 9.88, New mean = 57.44

About This Question

This is Waec Model Questions Vol1 2021 Mathematics Question 18. It is one of the objective questions from the 2021 Waec Model Questions Vol1 Mathematics examination.

Difficulty level: Hard .

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