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Finding the Fourth Proportional to 645, 890.14 and 396.59

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Solution

The fourth proportional to 645, 890.14 and 396.59 is: 547.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    645 : 890.14 = 396.59 : x
  2. Step 2: Convert to fraction form
    645/890.14 = 396.59/x
  3. Step 3: Cross multiply
    645x = 890.14 × 396.59
  4. Step 4: Simplify right side
    645x = 353,014.19
  5. Step 5: Solve for x
    x = 353,014.19/645
  6. Step 6: Final answer
    x = 547.31

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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.