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Finding the Fourth Proportional to 658.42, 987.72 and 521.72

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Solution

The fourth proportional to 658.42, 987.72 and 521.72 is: 782.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    658.42 : 987.72 = 521.72 : x
  2. Step 2: Convert to fraction form
    658.42/987.72 = 521.72/x
  3. Step 3: Cross multiply
    658.42x = 987.72 × 521.72
  4. Step 4: Simplify right side
    658.42x = 515,313.28
  5. Step 5: Solve for x
    x = 515,313.28/658.42
  6. Step 6: Final answer
    x = 782.65

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.