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Finding the Fourth Proportional to 428.37, 646.21 and 415.60

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Solution

The fourth proportional to 428.37, 646.21 and 415.60 is: 626.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.37 : 646.21 = 415.60 : x
  2. Step 2: Convert to fraction form
    428.37/646.21 = 415.60/x
  3. Step 3: Cross multiply
    428.37x = 646.21 × 415.60
  4. Step 4: Simplify right side
    428.37x = 268,564.88
  5. Step 5: Solve for x
    x = 268,564.88/428.37
  6. Step 6: Final answer
    x = 626.95

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.