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Finding the Fourth Proportional to 689.83, 951.92 and 390.99

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Solution

The fourth proportional to 689.83, 951.92 and 390.99 is: 539.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.83 : 951.92 = 390.99 : x
  2. Step 2: Convert to fraction form
    689.83/951.92 = 390.99/x
  3. Step 3: Cross multiply
    689.83x = 951.92 × 390.99
  4. Step 4: Simplify right side
    689.83x = 372,189.25
  5. Step 5: Solve for x
    x = 372,189.25/689.83
  6. Step 6: Final answer
    x = 539.54

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1.5x scale

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.