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Finding the Fourth Proportional to 715.57, 987.43 and 400.81

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Solution

The fourth proportional to 715.57, 987.43 and 400.81 is: 553.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.57 : 987.43 = 400.81 : x
  2. Step 2: Convert to fraction form
    715.57/987.43 = 400.81/x
  3. Step 3: Cross multiply
    715.57x = 987.43 × 400.81
  4. Step 4: Simplify right side
    715.57x = 395,771.82
  5. Step 5: Solve for x
    x = 395,771.82/715.57
  6. Step 6: Final answer
    x = 553.09

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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.