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Finding the Fourth Proportional to 631.78, 871.18 and 498.77

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Solution

The fourth proportional to 631.78, 871.18 and 498.77 is: 687.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.78 : 871.18 = 498.77 : x
  2. Step 2: Convert to fraction form
    631.78/871.18 = 498.77/x
  3. Step 3: Cross multiply
    631.78x = 871.18 × 498.77
  4. Step 4: Simplify right side
    631.78x = 434,518.45
  5. Step 5: Solve for x
    x = 434,518.45/631.78
  6. Step 6: Final answer
    x = 687.77

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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.