Statistical Representation, Central Tendency & Dispersion — Practice

Question 1

The average of 10 observations is 25. If one observation of 30 is removed, the new average is

Accepted Answer

A

Question 2

The mean of 20 observations is 15 and of another 30 observations is 25. The combined mean is

Accepted Answer

B

Question 3

For a distribution of annual incomes in which a few individuals earn extremely high amounts, the most appropriate measure of central tendency is

Accepted Answer

B

Question 4

In a moderately skewed distribution the mean is 32 and the median is 30. The mode is approximately

Accepted Answer

A

Question 5

If 5 is added to each observation of a set whose standard deviation is 8, the new standard deviation is

Accepted Answer

B

Question 6

Series A has mean 50 and standard deviation 10; series B has mean 80 and standard deviation 12. The more consistent series is

Accepted Answer

B

Question 7

The median of the observations 12, 15, 18, 22, 25, 30, 35 is

Accepted Answer

A

Question 8

The value of a share rises by 20% in the first year and by 80% in the second. The average annual rate of growth is

Accepted Answer

B

Question 9

The standard deviation of the first 10 natural numbers is approximately

Accepted Answer

A

Question 10

Two groups have n₁ = 50, x̄₁ = 60, σ₁ = 8 and n₂ = 50, x̄₂ = 70, σ₂ = 6. The combined standard deviation is closest to

Accepted Answer

B

Question 11

Mean deviation is minimum when computed from the

Accepted Answer

B

Question 12

For the inclusive classes 10-19, 20-29, 30-39, the class boundaries of the second class are

Accepted Answer

B

Question 13

A person travels from A to B at 40 km per hour and returns at 60 km per hour. The average speed for the whole journey is

Accepted Answer

B

Question 14

The mean of 100 items was found to be 40. Later it was discovered that an item recorded as 65 should have been 56. The corrected mean is

Accepted Answer

A

Question 15

Which of the following is unaffected by extreme values?

Accepted Answer

D

Practice — Statistical Representation, Central Tendency & Dispersion