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Finding the Fourth Proportional to 680.70, 938.94 and 428.79

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Solution

The fourth proportional to 680.70, 938.94 and 428.79 is: 591.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.70 : 938.94 = 428.79 : x
  2. Step 2: Convert to fraction form
    680.70/938.94 = 428.79/x
  3. Step 3: Cross multiply
    680.70x = 938.94 × 428.79
  4. Step 4: Simplify right side
    680.70x = 402,612.41
  5. Step 5: Solve for x
    x = 402,612.41/680.70
  6. Step 6: Final answer
    x = 591.46

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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.