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Finding the Fourth Proportional to 985.39, 1,479 and 498.78

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Solution

The fourth proportional to 985.39, 1,479 and 498.78 is: 748.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    985.39 : 1,479 = 498.78 : x
  2. Step 2: Convert to fraction form
    985.39/1,479 = 498.78/x
  3. Step 3: Cross multiply
    985.39x = 1,479 × 498.78
  4. Step 4: Simplify right side
    985.39x = 737,695.62
  5. Step 5: Solve for x
    x = 737,695.62/985.39
  6. Step 6: Final answer
    x = 748.63

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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.