Comparing Probabilities - ISEE Middle Level Mathematics Achievement

  1. Which probability is larger: 925\frac{9}{25} or 35%35\%?
    925\frac{9}{25}. Converting shows 925=0.36\frac{9}{25}=0.36 exceeds 35%=0.3535\%=0.35.
  2. Which probability is larger: P(E)P(E) or P(Ec)P(E^c) if P(E)=0.6P(E)=0.6?
    P(E)P(E). With P(E)=0.6P(E)=0.6, it exceeds P(Ec)=0.4P(E^c)=0.4.
  3. Which is more likely: rolling an even number or rolling a number greater than 44 on a fair die?
    Rolling an even number. Even numbers (2,4,6) have probability 36=0.5\frac{3}{6}=0.5, exceeding numbers greater than 4 (5,6) at 26≈0.333\frac{2}{6} \approx 0.333.
  4. Which probability is larger: 1350\frac{13}{50} or 0.270.27?
    0.270.27. 0.270.27 is greater than 1350=0.26\frac{13}{50}=0.26 in decimal form.
  5. Which probability is larger: 0.370.37 or 310\frac{3}{10}?
    0.370.37. 0.370.37 exceeds 310=0.3\frac{3}{10}=0.3 when compared directly as decimals.
  6. Which probability is larger: 1130\frac{11}{30} or 38\frac{3}{8}?
    38\frac{3}{8}. Converting to decimals indicates 38=0.375\frac{3}{8}=0.375 is greater than 1130≈0.367\frac{11}{30} \approx 0.367.
  7. What is the probability of an event EE in terms of favorable and total outcomes?
    P(E)=favorabletotalP(E)=\frac{\text{favorable}}{\text{total}}. Probability measures the likelihood as the ratio of favorable outcomes to total possible outcomes in a uniform sample space.
  8. Which probability is larger: 49\frac{4}{9} or 0.450.45?
    0.450.45. 0.450.45 slightly exceeds 49≈0.444\frac{4}{9} \approx 0.444 when compared as decimals.
  9. Which probability is larger: 14\frac{1}{4} or 0.260.26?
    0.260.26. 0.260.26 exceeds 14=0.25\frac{1}{4}=0.25 when compared directly.
  10. Which probability is larger: P(E)P(E) or P(Ec)P(E^c) if P(E)=25P(E)=\frac{2}{5}?
    P(Ec)P(E^c). Given P(E)=25=0.4P(E)=\frac{2}{5}=0.4, P(Ec)=0.6P(E^c)=0.6 is larger.
  11. Which probability is larger: 38\frac{3}{8} or 25\frac{2}{5}?
    25\frac{2}{5}. Converting to decimals shows 25=0.4\frac{2}{5}=0.4 exceeds 38=0.375\frac{3}{8}=0.375.
  12. Which probability is closest to 12\frac{1}{2}: 0.490.49, 0.520.52, or 0.60.6?
    0.490.49. 0.490.49 is closest to 0.50.5, being only 0.010.01 away compared to 0.020.02 for 0.520.52 and 0.10.1 for 0.60.6.
  13. Which probability is larger: 58\frac{5}{8} or 62%62\%?
    58\frac{5}{8}. Converting shows 58=0.625\frac{5}{8}=0.625 exceeds 62%=0.6262\%=0.62.
  14. Which probability is larger: 37\frac{3}{7} or 49\frac{4}{9}?
    49\frac{4}{9}. Converting to decimals reveals 49≈0.444\frac{4}{9} \approx 0.444 is greater than 37≈0.429\frac{3}{7} \approx 0.429.
  15. Which probability is larger: 720\frac{7}{20} or 0.360.36?
    0.360.36. 0.360.36 is greater than 720=0.35\frac{7}{20}=0.35 when compared as decimals.
  16. What is the complement rule for an event EE?
    P(Ec)=1−P(E)P(E^c)=1-P(E). The complement rule states that the probability of an event not occurring is one minus the probability of it occurring.
  17. Which probability is larger: 1740\frac{17}{40} or 0.410.41?
    1740\frac{17}{40}. Converting shows 1740=0.425\frac{17}{40}=0.425 exceeds 0.410.41.
  18. Which probability is larger: 512\frac{5}{12} or 23\frac{2}{3}?
    23\frac{2}{3}. Converting to decimals reveals 23≈0.667\frac{2}{3} \approx 0.667 is greater than 512≈0.417\frac{5}{12} \approx 0.417.
  19. Which probability is larger: 0.1250.125 or 19\frac{1}{9}?
    0.1250.125. 0.1250.125 exceeds 19≈0.111\frac{1}{9} \approx 0.111 when compared as decimals.
  20. Which probability is larger: 45%45\% or 0.430.43?
    45%45\%. Converting 45%45\% to 0.450.45 shows it exceeds 0.430.43.
  21. Which is more likely: 33 heads in 33 fair coin flips or 00 heads in 33 flips?
    They are equally likely. Both outcomes have probability 18\frac{1}{8} in a binomial distribution with fair coins.
  22. Which probability is closest to 11: 78\frac{7}{8}, 56\frac{5}{6}, or 910\frac{9}{10}?
    910\frac{9}{10}. 910=0.9\frac{9}{10}=0.9 is nearest to 11, compared to 78=0.875\frac{7}{8}=0.875 and 56≈0.833\frac{5}{6} \approx 0.833.

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