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Finding the Fourth Proportional to 613.12, 920.40 and 430

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Solution

The fourth proportional to 613.12, 920.40 and 430 is: 645.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    613.12 : 920.40 = 430 : x
  2. Step 2: Convert to fraction form
    613.12/920.40 = 430/x
  3. Step 3: Cross multiply
    613.12x = 920.40 × 430
  4. Step 4: Simplify right side
    613.12x = 395,772
  5. Step 5: Solve for x
    x = 395,772/613.12
  6. Step 6: Final answer
    x = 645.50

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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.