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Finding the Fourth Proportional to 645.80, 891.21 and 351.07

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Solution

The fourth proportional to 645.80, 891.21 and 351.07 is: 484.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.80 : 891.21 = 351.07 : x
  2. Step 2: Convert to fraction form
    645.80/891.21 = 351.07/x
  3. Step 3: Cross multiply
    645.80x = 891.21 × 351.07
  4. Step 4: Simplify right side
    645.80x = 312,875.88
  5. Step 5: Solve for x
    x = 312,875.88/645.80
  6. Step 6: Final answer
    x = 484.48

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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.