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Finding the Fourth Proportional to 288.90, 430.38 and 280.40

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Solution

The fourth proportional to 288.90, 430.38 and 280.40 is: 417.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    288.90 : 430.38 = 280.40 : x
  2. Step 2: Convert to fraction form
    288.90/430.38 = 280.40/x
  3. Step 3: Cross multiply
    288.90x = 430.38 × 280.40
  4. Step 4: Simplify right side
    288.90x = 120,676.40
  5. Step 5: Solve for x
    x = 120,676.40/288.90
  6. Step 6: Final answer
    x = 417.71

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.