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Finding the Fourth Proportional to 626.22, 939.66 and 420.90

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Solution

The fourth proportional to 626.22, 939.66 and 420.90 is: 631.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    626.22 : 939.66 = 420.90 : x
  2. Step 2: Convert to fraction form
    626.22/939.66 = 420.90/x
  3. Step 3: Cross multiply
    626.22x = 939.66 × 420.90
  4. Step 4: Simplify right side
    626.22x = 395,502.89
  5. Step 5: Solve for x
    x = 395,502.89/626.22
  6. Step 6: Final answer
    x = 631.57

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.