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Finding the Fourth Proportional to 817.72, 1,128.98 and 630.88

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Solution

The fourth proportional to 817.72, 1,128.98 and 630.88 is: 871.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    817.72 : 1,128.98 = 630.88 : x
  2. Step 2: Convert to fraction form
    817.72/1,128.98 = 630.88/x
  3. Step 3: Cross multiply
    817.72x = 1,128.98 × 630.88
  4. Step 4: Simplify right side
    817.72x = 712,249.66
  5. Step 5: Solve for x
    x = 712,249.66/817.72
  6. Step 6: Final answer
    x = 871.02

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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.