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Finding the Fourth Proportional to 289.60, 434.40 and 255.40

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Solution

The fourth proportional to 289.60, 434.40 and 255.40 is: 383.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.60 : 434.40 = 255.40 : x
  2. Step 2: Convert to fraction form
    289.60/434.40 = 255.40/x
  3. Step 3: Cross multiply
    289.60x = 434.40 × 255.40
  4. Step 4: Simplify right side
    289.60x = 110,945.76
  5. Step 5: Solve for x
    x = 110,945.76/289.60
  6. Step 6: Final answer
    x = 383.10

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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.