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Finding the Fourth Proportional to 613.30, 918.60 and 429.70

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Solution

The fourth proportional to 613.30, 918.60 and 429.70 is: 643.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    613.30 : 918.60 = 429.70 : x
  2. Step 2: Convert to fraction form
    613.30/918.60 = 429.70/x
  3. Step 3: Cross multiply
    613.30x = 918.60 × 429.70
  4. Step 4: Simplify right side
    613.30x = 394,722.42
  5. Step 5: Solve for x
    x = 394,722.42/613.30
  6. Step 6: Final answer
    x = 643.60

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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.