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Finding the Fourth Proportional to 782.39, 1,079.80 and 487.82

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Solution

The fourth proportional to 782.39, 1,079.80 and 487.82 is: 673.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    782.39 : 1,079.80 = 487.82 : x
  2. Step 2: Convert to fraction form
    782.39/1,079.80 = 487.82/x
  3. Step 3: Cross multiply
    782.39x = 1,079.80 × 487.82
  4. Step 4: Simplify right side
    782.39x = 526,749.52
  5. Step 5: Solve for x
    x = 526,749.52/782.39
  6. Step 6: Final answer
    x = 673.25

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1.5x scale

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.