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Finding the Fourth Proportional to 777.76, 1,165.68 and 392.80

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Solution

The fourth proportional to 777.76, 1,165.68 and 392.80 is: 588.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    777.76 : 1,165.68 = 392.80 : x
  2. Step 2: Convert to fraction form
    777.76/1,165.68 = 392.80/x
  3. Step 3: Cross multiply
    777.76x = 1,165.68 × 392.80
  4. Step 4: Simplify right side
    777.76x = 457,879.10
  5. Step 5: Solve for x
    x = 457,879.10/777.76
  6. Step 6: Final answer
    x = 588.72

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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.