MEDIUM
NDA & NA EE
IMPORTANT
Earn 100

The harmonic mean H of two numbers is 4 and the arithmetic mean A and geometric mean G satisfy the equation 2A+G2=27. The two numbers are

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Important Questions on Statistics

HARD
NDA & NA EE
IMPORTANT
Pathfinder NDA / NA National Defence Academy and Naval Academy Entrance Examination Mathematics>Chapter 31 - Statistics>Practice Exercise>Q 52

Consider the following frequency distribution

Class interval 0-10 10-20 20-30 30-40 40-50
Frequency 14 x 27 y 15

If the total of the frequencies is 100 and mode is 25, then which one of the following is correct?

EASY
NDA & NA EE
IMPORTANT
Pathfinder NDA / NA National Defence Academy and Naval Academy Entrance Examination Mathematics>Chapter 31 - Statistics>Practice Exercise>Q 53
The marks obtained by 13 students in a test are 10, 3, 10, 12, 9, 7,9, 6, 7, 10, 8, 6 and 7. The median of this data is
EASY
NDA & NA EE
IMPORTANT
Pathfinder NDA / NA National Defence Academy and Naval Academy Entrance Examination Mathematics>Chapter 31 - Statistics>Practice Exercise>Q 54
Consider the following statements
I. Both variance and standard deviation are measures of variability in the population.
II. The standard deviation is the square of the variance. Which of the above statement(s) is/are correct?
EASY
NDA & NA EE
IMPORTANT
Pathfinder NDA / NA National Defence Academy and Naval Academy Entrance Examination Mathematics>Chapter 31 - Statistics>Practice Exercise>Q 55
Coefficient of correlation is the measure of
EASY
NDA & NA EE
IMPORTANT
Pathfinder NDA / NA National Defence Academy and Naval Academy Entrance Examination Mathematics>Chapter 31 - Statistics>Practice Exercise>Q 56
Which one of the following measures is determined only after the construction of cumulative frequency distribution?
EASY
NDA & NA EE
IMPORTANT
Pathfinder NDA / NA National Defence Academy and Naval Academy Entrance Examination Mathematics>Chapter 31 - Statistics>Practice Exercise>Q 57
The arithmetic mean of the squares of the first n natural numbers is
EASY
NDA & NA EE
IMPORTANT
Pathfinder NDA / NA National Defence Academy and Naval Academy Entrance Examination Mathematics>Chapter 31 - Statistics>Practice Exercise>Q 58
The mean of 20 observations is 15. On checking, it was found that two observations were wrongly copied as 3 and 6. If the wrong observations are replaced by correct values 8 and 4, then the correct mean is
MEDIUM
NDA & NA EE
IMPORTANT
Pathfinder NDA / NA National Defence Academy and Naval Academy Entrance Examination Mathematics>Chapter 31 - Statistics>Practice Exercise>Q 59

Consider the following statements:

I. Both the regression coefficients have the same sign.

II. If one of the regression coefficients is greater than unity, the other must be less than unity.

Which of the above statement(s) is / are correct?