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Finding the Fourth Proportional to 612.65, 918.98 and 430.86

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Solution

The fourth proportional to 612.65, 918.98 and 430.86 is: 646.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    612.65 : 918.98 = 430.86 : x
  2. Step 2: Convert to fraction form
    612.65/918.98 = 430.86/x
  3. Step 3: Cross multiply
    612.65x = 918.98 × 430.86
  4. Step 4: Simplify right side
    612.65x = 395,951.18
  5. Step 5: Solve for x
    x = 395,951.18/612.65
  6. Step 6: Final answer
    x = 646.29

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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.