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Finding the Fourth Proportional to 768.91, 1,153.30 and 398.70

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Solution

The fourth proportional to 768.91, 1,153.30 and 398.70 is: 598.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    768.91 : 1,153.30 = 398.70 : x
  2. Step 2: Convert to fraction form
    768.91/1,153.30 = 398.70/x
  3. Step 3: Cross multiply
    768.91x = 1,153.30 × 398.70
  4. Step 4: Simplify right side
    768.91x = 459,820.46
  5. Step 5: Solve for x
    x = 459,820.46/768.91
  6. Step 6: Final answer
    x = 598.01

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.