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Finding the Fourth Proportional to 417.70, 626.55 and 390.70

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Solution

The fourth proportional to 417.70, 626.55 and 390.70 is: 586.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    417.70 : 626.55 = 390.70 : x
  2. Step 2: Convert to fraction form
    417.70/626.55 = 390.70/x
  3. Step 3: Cross multiply
    417.70x = 626.55 × 390.70
  4. Step 4: Simplify right side
    417.70x = 244,793.09
  5. Step 5: Solve for x
    x = 244,793.09/417.70
  6. Step 6: Final answer
    x = 586.05

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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.