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Finding the Fourth Proportional to 289.80, 434.70 and 284.40

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Solution

The fourth proportional to 289.80, 434.70 and 284.40 is: 426.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.80 : 434.70 = 284.40 : x
  2. Step 2: Convert to fraction form
    289.80/434.70 = 284.40/x
  3. Step 3: Cross multiply
    289.80x = 434.70 × 284.40
  4. Step 4: Simplify right side
    289.80x = 123,628.68
  5. Step 5: Solve for x
    x = 123,628.68/289.80
  6. Step 6: Final answer
    x = 426.60

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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.