Probability and Statistics - Online Test
Q1. The letters of the word ‘ MALENKOV ‘are arranged in all possible ways. The chance that there are exactly four letters between M and E is
Answer : Option D
Explaination / Solution:
No Explaination.
Q2. 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
Q3.
Direction: Study the given information carefully and answer the questions that follow—
A store contains 3 red, 4 blue, 4 green and 4 whites’ bats.
If two bats are picked at random, what is the probability that both are white?
Answer : Option D
Explaination / Solution:
Probabilities if both are White
4C2/15C2 = 6/105 → 2/35
Q4. The letters of the word ‘ ORIENTAL ‘ are arranged in all possible ways . The chance that the consonants and vowels occur alternately is
Answer : Option C
Explaination / Solution:
No Explaination.
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 four bats are picked at random, what is the probability that two are blue and two is green?
Answer : Option A
Explaination / Solution:
Probability if two are Blue and two are Green =
[(4C2*4C2)/15C4] = (6*6)/1365 → 12/455
Q7. 8 coins are tossed at a time. The probability of getting atleast 6 heads up is
Answer : Option D
Explaination / Solution:
No Explaination.
Q8. 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,
Q9. If three bats are picked at random, what is the probability that at least one is green?
Answer : Option D
Explaination / Solution:
Probability if at least one is green
[1-(11C3/15C3)] = [1-(165/455)] → 58/91
Q10. There are 2 boxes. One box contains 3 white balls and 2 black balls. The other box contains 7 yellow balls and 3 black balls. If a box is selected at random and from it, a ball is drawn , the probability that the ball drawn is black is
Answer : Option D
Explaination / Solution:
No Explaination.
