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Finding the Fourth Proportional to 421.91, 627.85 and 405.51

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Solution

The fourth proportional to 421.91, 627.85 and 405.51 is: 603.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.91 : 627.85 = 405.51 : x
  2. Step 2: Convert to fraction form
    421.91/627.85 = 405.51/x
  3. Step 3: Cross multiply
    421.91x = 627.85 × 405.51
  4. Step 4: Simplify right side
    421.91x = 254,597.61
  5. Step 5: Solve for x
    x = 254,597.61/421.91
  6. Step 6: Final answer
    x = 603.44

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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.