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Finding the Fourth Proportional to 678.14, 1,017.20 and 191.19

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Solution

The fourth proportional to 678.14, 1,017.20 and 191.19 is: 286.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.14 : 1,017.20 = 191.19 : x
  2. Step 2: Convert to fraction form
    678.14/1,017.20 = 191.19/x
  3. Step 3: Cross multiply
    678.14x = 1,017.20 × 191.19
  4. Step 4: Simplify right side
    678.14x = 194,478.47
  5. Step 5: Solve for x
    x = 194,478.47/678.14
  6. Step 6: Final answer
    x = 286.78

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.