Statistics - Online Test
Q1. Which of the following is not a measure of dispersion ?
Answer : Option D
Explaination / Solution:
it is the measure of central tendency
Q2. The mean and S.D. of 1,2,3,4,5,6 is
Answer : Option C
Explaination / Solution:
Q3. The range of the following set of observations 2,3,5,9,8,7,6,5,7,4,3 is
Answer : Option A
Explaination / Solution:
range= 9- 2 = 7
Q4. Which of the following, in case of a discrete data, is not equal to the median?
Answer : Option C
Explaination / Solution:
As lower quartile is the whereas median is or the average of middle most terms
Q5. Mean deviation from the mean for the observations – 1 , 0 ,4 is
Answer : Option C
Explaination / Solution:
mean=−1+0+43=3/3=1M.D=1n∣∣∑(Xi−X¯)∣∣=2+1+33=2
Q6. If the two lines of regression are 2x + y =7 and x + 2y = 7, then ρ(X,Y) is equal to
Answer : Option B
Explaination / Solution:
let us assume that 2x + y =7 and x + 2y = 7 are lines of regression of y on x and x on y respectively
therefore,
but sign of p will be same as and
hence,
Q7. The mean of 50 observations is 36, if two observations are 30 and 42 are deleted , then the mean of the remaining observations is
Answer : Option D
Explaination / Solution:
After deleting the observations 30 and 42
new sum
new mean
Q8. For a bivariate frequency distribution then is
Answer : Option D
Explaination / Solution:
if then
Q9. A man travels at a speed of 20 km/hour and then return at a speed of 30 km/hour. His average speed of the whole journey is
Answer : Option A
Explaination / Solution:
average speed for whole journey is the H.M between 20 and 30
therefore, average speed km/hr
Q10. The S.D. of the first n natural numbers is
Answer : Option A
Explaination / Solution:
first n natural numbers are 1,2,3.....n
we know that,
sum of sqaure is
