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Finding the Fourth Proportional to 782.40, 1,079.58 and 487.76

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Solution

The fourth proportional to 782.40, 1,079.58 and 487.76 is: 673.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    782.40 : 1,079.58 = 487.76 : x
  2. Step 2: Convert to fraction form
    782.40/1,079.58 = 487.76/x
  3. Step 3: Cross multiply
    782.40x = 1,079.58 × 487.76
  4. Step 4: Simplify right side
    782.40x = 526,575.94
  5. Step 5: Solve for x
    x = 526,575.94/782.40
  6. Step 6: Final answer
    x = 673.03

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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.