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Finding the Fourth Proportional to 492.21, 679.19 and 317.79

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Solution

The fourth proportional to 492.21, 679.19 and 317.79 is: 438.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    492.21 : 679.19 = 317.79 : x
  2. Step 2: Convert to fraction form
    492.21/679.19 = 317.79/x
  3. Step 3: Cross multiply
    492.21x = 679.19 × 317.79
  4. Step 4: Simplify right side
    492.21x = 215,838.20
  5. Step 5: Solve for x
    x = 215,838.20/492.21
  6. Step 6: Final answer
    x = 438.51

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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.