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Finding the Fourth Proportional to 689.81, 951.60 and 394.90

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Solution

The fourth proportional to 689.81, 951.60 and 394.90 is: 544.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.81 : 951.60 = 394.90 : x
  2. Step 2: Convert to fraction form
    689.81/951.60 = 394.90/x
  3. Step 3: Cross multiply
    689.81x = 951.60 × 394.90
  4. Step 4: Simplify right side
    689.81x = 375,789.51
  5. Step 5: Solve for x
    x = 375,789.51/689.81
  6. Step 6: Final answer
    x = 544.78

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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.