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Finding the Fourth Proportional to 719.80, 993.18 and 498.40

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Solution

The fourth proportional to 719.80, 993.18 and 498.40 is: 687.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    719.80 : 993.18 = 498.40 : x
  2. Step 2: Convert to fraction form
    719.80/993.18 = 498.40/x
  3. Step 3: Cross multiply
    719.80x = 993.18 × 498.40
  4. Step 4: Simplify right side
    719.80x = 495,000.91
  5. Step 5: Solve for x
    x = 495,000.91/719.80
  6. Step 6: Final answer
    x = 687.69

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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.