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Finding the Fourth Proportional to 782.80, 1,175.40 and 458.80

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Solution

The fourth proportional to 782.80, 1,175.40 and 458.80 is: 688.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    782.80 : 1,175.40 = 458.80 : x
  2. Step 2: Convert to fraction form
    782.80/1,175.40 = 458.80/x
  3. Step 3: Cross multiply
    782.80x = 1,175.40 × 458.80
  4. Step 4: Simplify right side
    782.80x = 539,273.52
  5. Step 5: Solve for x
    x = 539,273.52/782.80
  6. Step 6: Final answer
    x = 688.90

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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.