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Finding the Fourth Proportional to 645.53, 890.70 and 409.55

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Solution

The fourth proportional to 645.53, 890.70 and 409.55 is: 565.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.53 : 890.70 = 409.55 : x
  2. Step 2: Convert to fraction form
    645.53/890.70 = 409.55/x
  3. Step 3: Cross multiply
    645.53x = 890.70 × 409.55
  4. Step 4: Simplify right side
    645.53x = 364,786.19
  5. Step 5: Solve for x
    x = 364,786.19/645.53
  6. Step 6: Final answer
    x = 565.10

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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.