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Finding the Fourth Proportional to 645, 890.12 and 412.28

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Solution

The fourth proportional to 645, 890.12 and 412.28 is: 568.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    645 : 890.12 = 412.28 : x
  2. Step 2: Convert to fraction form
    645/890.12 = 412.28/x
  3. Step 3: Cross multiply
    645x = 890.12 × 412.28
  4. Step 4: Simplify right side
    645x = 366,978.67
  5. Step 5: Solve for x
    x = 366,978.67/645
  6. Step 6: Final answer
    x = 568.96

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.