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Finding the Fourth Proportional to 645.70, 891.32 and 436

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Solution

The fourth proportional to 645.70, 891.32 and 436 is: 601.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.70 : 891.32 = 436 : x
  2. Step 2: Convert to fraction form
    645.70/891.32 = 436/x
  3. Step 3: Cross multiply
    645.70x = 891.32 × 436
  4. Step 4: Simplify right side
    645.70x = 388,615.52
  5. Step 5: Solve for x
    x = 388,615.52/645.70
  6. Step 6: Final answer
    x = 601.85

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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.