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Finding the Fourth Proportional to 792.90, 1,089.27 and 645.12

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Solution

The fourth proportional to 792.90, 1,089.27 and 645.12 is: 886.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    792.90 : 1,089.27 = 645.12 : x
  2. Step 2: Convert to fraction form
    792.90/1,089.27 = 645.12/x
  3. Step 3: Cross multiply
    792.90x = 1,089.27 × 645.12
  4. Step 4: Simplify right side
    792.90x = 702,709.86
  5. Step 5: Solve for x
    x = 702,709.86/792.90
  6. Step 6: Final answer
    x = 886.25

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.