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Finding the Fourth Proportional to 859.24, 1,288.14 and 642.88

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Solution

The fourth proportional to 859.24, 1,288.14 and 642.88 is: 963.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.24 : 1,288.14 = 642.88 : x
  2. Step 2: Convert to fraction form
    859.24/1,288.14 = 642.88/x
  3. Step 3: Cross multiply
    859.24x = 1,288.14 × 642.88
  4. Step 4: Simplify right side
    859.24x = 828,119.44
  5. Step 5: Solve for x
    x = 828,119.44/859.24
  6. Step 6: Final answer
    x = 963.78

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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.