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Finding the Fourth Proportional to 631.79, 871.79 and 383.21

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Solution

The fourth proportional to 631.79, 871.79 and 383.21 is: 528.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.79 : 871.79 = 383.21 : x
  2. Step 2: Convert to fraction form
    631.79/871.79 = 383.21/x
  3. Step 3: Cross multiply
    631.79x = 871.79 × 383.21
  4. Step 4: Simplify right side
    631.79x = 334,072.37
  5. Step 5: Solve for x
    x = 334,072.37/631.79
  6. Step 6: Final answer
    x = 528.78

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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.