All Free Statistics MCQs with Answers

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545 questions · page 49 of 55

481. If in a coin P(H) = 2P(T) then prob. of head is ______________?

Moderate
  • A. 1/3
  • B. 2/3
  • C. 1/2
  • D. 0

Explanation: Let P(T)=p, so P(H)=2p. Since P(H)+P(T)=1, 3p=1 and therefore P(H)=2/3.

Correct answer: 2/3

482. If P(A/B)=1/4 and P(A∩B) =1/5 then P(B) is ________________?

Moderate
  • A. 4/5
  • B. 1/20
  • C. 0
  • D. 1/9

Explanation: Using P(A|B)=P(A∩B)/P(B), we get 1/4=(1/5)/P(B). Rearranging gives P(B)=4/5.

Correct answer: 4/5

483. The probability of getting at least one head when two balance coins are tossed once __________________?

Moderate
  • A. 1/4
  • B. 2/4
  • C. 3/4
  • D. 4/4

Explanation: With two fair coins, the four equally likely outcomes are HH, HT, TH, and TT. Three contain at least one head, so the probability is 3/4.

Correct answer: 3/4

484. The probability of getting exactly three tails when three balanced coins are tossed once _______________?

Moderate
  • A. 1/8
  • B. 2/8
  • C. 5/8
  • D. 7/8

Explanation: Only one outcome, tails-tails-tails, gives exactly three tails. With three fair coins there are 2^3 = 8 equally likely outcomes, so the probability is 1/8.

Correct answer: 1/8

485. The probability that the sum is odd if two dice are thrown:_________________?

Moderate
  • A. 18/36
  • B. 9/36
  • C. 6/36
  • D. 12/36

Explanation: A sum of two dice is odd when one die shows an odd number and the other an even number. There are 3 × 3 + 3 × 3 = 18 such outcomes out of 36, giving 18/36.

Correct answer: 18/36

486. A box containing 12 balls of color 6 red and 6 white. A ball of white selected ball finds the probability of white____________?

Moderate
  • A. 7/12
  • B. 6/12
  • C. 12/12
  • D. 4/12

Explanation: The probability is favourable outcomes divided by total outcomes. Six white balls out of 12 balls give 6/12, which can also be simplified to 1/2.

Correct answer: 6/12

487. The probability of drawing an even number in a toss of a balanced die ______________?

Moderate
  • A. 1/6
  • B. 2/6
  • C. 3/6
  • D. 6/6

Explanation: The even outcomes on a die are 2, 4, and 6, giving three favourable outcomes out of six. Therefore the probability is 3/6, or 1/2.

Correct answer: 3/6

488. The probability of drawing a picture card out of 52 cards is : ______________?

Moderate
  • A. 13/52
  • B. 12/52
  • C. 16/52
  • D. 3/52

Explanation: Picture cards are jacks, queens, and kings: 3 ranks in each of 4 suits, making 12 cards. Hence the probability is 12/52, which simplifies to 3/13.

Correct answer: 12/52

489. The probability of an event cannot be _____________?

Moderate
  • A. Positive
  • B. Zero
  • C. None of these
  • D. Negative

Explanation: Probability ranges from 0 to 1, so it may be zero but cannot be negative. A negative value has no meaning as an event probability.

Correct answer: Negative

490. If an event consists of only one sample point is called _____________?

Moderate
  • A. Appeared
  • B. Exactly
  • C. Space
  • D. Elementary event

Explanation: An elementary event contains exactly one sample point, such as obtaining a six when rolling a die. The other choices are not the standard term for this event.

Correct answer: Elementary event