Frosina performed an experiment in which she randomly pulled a marble from a bag, recorded its color, put it back, and then repeated the process. The following table represents the number of times each color of marble was pulled.



Color of Marble
Number of Times Pulled
Purple

18

Blue

6

Yellow

12



Which bag of marbles best models this experiment?

Responses

6 purple, 1 blue, 9 yellow

6 purple, 6 blue, 2 yellow

6 purple, 2 blue, 4 yellow

4 purple, 5 blue, 2 yellow

1 answer

To determine which bag of marbles best models Frosina's experiment, we need to analyze the ratios of the colors of marbles pulled from the bag based on the number of times each color was recorded.

Frosina pulled the marbles a total of:

\[ 18 \text{ (purple)} + 6 \text{ (blue)} + 12 \text{ (yellow)} = 36 \text{ total pulls} \]

Now, let's calculate the proportion for each color based on the total number of pulls:

  • Purple: \[ \frac{18}{36} = \frac{1}{2} \]

  • Blue: \[ \frac{6}{36} = \frac{1}{6} \]

  • Yellow: \[ \frac{12}{36} = \frac{1}{3} \]

Next, we will check the options given in the responses to see which bag has a similar ratio.

Let's analyze each response:

  1. 6 purple, 1 blue, 9 yellow:

    • Total = \(6 + 1 + 9 = 16\)
    • Ratio: \(\frac{6}{16} : \frac{1}{16} : \frac{9}{16} = \frac{3}{8} : \frac{1}{16} : \frac{9}{16} \), which does not match.
  2. 6 purple, 6 blue, 2 yellow:

    • Total = \(6 + 6 + 2 = 14\)
    • Ratio: \(\frac{6}{14} : \frac{6}{14} : \frac{2}{14} = \frac{3}{7} : \frac{3}{7} : \frac{1}{7} \), which does not match.
  3. 6 purple, 2 blue, 4 yellow:

    • Total = \(6 + 2 + 4 = 12\)
    • Ratio: \(\frac{6}{12} : \frac{2}{12} : \frac{4}{12} = \frac{1}{2} : \frac{1}{6} : \frac{1}{3} \), which matches.
  4. 4 purple, 5 blue, 2 yellow:

    • Total = \(4 + 5 + 2 = 11\)
    • Ratio: \(\frac{4}{11} : \frac{5}{11} : \frac{2}{11}\), which does not match.

The only bag that matches the ratios of \( \frac{1}{2} : \frac{1}{6} : \frac{1}{3} \) derived from Frosina's experiment is therefore the third option:

6 purple, 2 blue, 4 yellow.