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Finding the Fourth Proportional to 420.64, 628.47 and 406.28

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Solution

The fourth proportional to 420.64, 628.47 and 406.28 is: 607.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.64 : 628.47 = 406.28 : x
  2. Step 2: Convert to fraction form
    420.64/628.47 = 406.28/x
  3. Step 3: Cross multiply
    420.64x = 628.47 × 406.28
  4. Step 4: Simplify right side
    420.64x = 255,336.36
  5. Step 5: Solve for x
    x = 255,336.36/420.64
  6. Step 6: Final answer
    x = 607.02

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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.