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Finding the Fourth Proportional to 680.40, 938.61 and 431.30

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Solution

The fourth proportional to 680.40, 938.61 and 431.30 is: 594.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.40 : 938.61 = 431.30 : x
  2. Step 2: Convert to fraction form
    680.40/938.61 = 431.30/x
  3. Step 3: Cross multiply
    680.40x = 938.61 × 431.30
  4. Step 4: Simplify right side
    680.40x = 404,824.84
  5. Step 5: Solve for x
    x = 404,824.84/680.40
  6. Step 6: Final answer
    x = 594.98

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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.