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Finding the Fourth Proportional to 816.90, 1,126.90 and 521.86

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Solution

The fourth proportional to 816.90, 1,126.90 and 521.86 is: 719.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    816.90 : 1,126.90 = 521.86 : x
  2. Step 2: Convert to fraction form
    816.90/1,126.90 = 521.86/x
  3. Step 3: Cross multiply
    816.90x = 1,126.90 × 521.86
  4. Step 4: Simplify right side
    816.90x = 588,084.03
  5. Step 5: Solve for x
    x = 588,084.03/816.90
  6. Step 6: Final answer
    x = 719.90

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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.