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Finding the Fourth Proportional to 420.08, 580.28 and 288.84

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Solution

The fourth proportional to 420.08, 580.28 and 288.84 is: 398.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.08 : 580.28 = 288.84 : x
  2. Step 2: Convert to fraction form
    420.08/580.28 = 288.84/x
  3. Step 3: Cross multiply
    420.08x = 580.28 × 288.84
  4. Step 4: Simplify right side
    420.08x = 167,608.08
  5. Step 5: Solve for x
    x = 167,608.08/420.08
  6. Step 6: Final answer
    x = 398.99

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.