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Finding the Fourth Proportional to 855.87, 1,283.98 and 279.15

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Solution

The fourth proportional to 855.87, 1,283.98 and 279.15 is: 418.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    855.87 : 1,283.98 = 279.15 : x
  2. Step 2: Convert to fraction form
    855.87/1,283.98 = 279.15/x
  3. Step 3: Cross multiply
    855.87x = 1,283.98 × 279.15
  4. Step 4: Simplify right side
    855.87x = 358,423.02
  5. Step 5: Solve for x
    x = 358,423.02/855.87
  6. Step 6: Final answer
    x = 418.78

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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.