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Finding the Fourth Proportional to 666.21, 999.36 and 521.67

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Solution

The fourth proportional to 666.21, 999.36 and 521.67 is: 782.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.21 : 999.36 = 521.67 : x
  2. Step 2: Convert to fraction form
    666.21/999.36 = 521.67/x
  3. Step 3: Cross multiply
    666.21x = 999.36 × 521.67
  4. Step 4: Simplify right side
    666.21x = 521,336.13
  5. Step 5: Solve for x
    x = 521,336.13/666.21
  6. Step 6: Final answer
    x = 782.54

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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.