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Finding the Fourth Proportional to 691, 1,036.08 and 279.78

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Solution

The fourth proportional to 691, 1,036.08 and 279.78 is: 419.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    691 : 1,036.08 = 279.78 : x
  2. Step 2: Convert to fraction form
    691/1,036.08 = 279.78/x
  3. Step 3: Cross multiply
    691x = 1,036.08 × 279.78
  4. Step 4: Simplify right side
    691x = 289,874.46
  5. Step 5: Solve for x
    x = 289,874.46/691
  6. Step 6: Final answer
    x = 419.50

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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.