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Finding the Fourth Proportional to 645.65, 890.43 and 580.37

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Solution

The fourth proportional to 645.65, 890.43 and 580.37 is: 800.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.65 : 890.43 = 580.37 : x
  2. Step 2: Convert to fraction form
    645.65/890.43 = 580.37/x
  3. Step 3: Cross multiply
    645.65x = 890.43 × 580.37
  4. Step 4: Simplify right side
    645.65x = 516,774.41
  5. Step 5: Solve for x
    x = 516,774.41/645.65
  6. Step 6: Final answer
    x = 800.40

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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.