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Finding the Fourth Proportional to 715.77, 987.70 and 396.75

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Solution

The fourth proportional to 715.77, 987.70 and 396.75 is: 547.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.77 : 987.70 = 396.75 : x
  2. Step 2: Convert to fraction form
    715.77/987.70 = 396.75/x
  3. Step 3: Cross multiply
    715.77x = 987.70 × 396.75
  4. Step 4: Simplify right side
    715.77x = 391,868.99
  5. Step 5: Solve for x
    x = 391,868.99/715.77
  6. Step 6: Final answer
    x = 547.48

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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.