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Finding the Fourth Proportional to 782.36, 1,079.55 and 487.64

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Solution

The fourth proportional to 782.36, 1,079.55 and 487.64 is: 672.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    782.36 : 1,079.55 = 487.64 : x
  2. Step 2: Convert to fraction form
    782.36/1,079.55 = 487.64/x
  3. Step 3: Cross multiply
    782.36x = 1,079.55 × 487.64
  4. Step 4: Simplify right side
    782.36x = 526,431.76
  5. Step 5: Solve for x
    x = 526,431.76/782.36
  6. Step 6: Final answer
    x = 672.88

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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.