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Finding the Fourth Proportional to 715.46, 987.21 and 420.62

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Solution

The fourth proportional to 715.46, 987.21 and 420.62 is: 580.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.46 : 987.21 = 420.62 : x
  2. Step 2: Convert to fraction form
    715.46/987.21 = 420.62/x
  3. Step 3: Cross multiply
    715.46x = 987.21 × 420.62
  4. Step 4: Simplify right side
    715.46x = 415,240.27
  5. Step 5: Solve for x
    x = 415,240.27/715.46
  6. Step 6: Final answer
    x = 580.38

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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.