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Finding the Fourth Proportional to 492.90, 679.86 and 318.30

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Solution

The fourth proportional to 492.90, 679.86 and 318.30 is: 439.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    492.90 : 679.86 = 318.30 : x
  2. Step 2: Convert to fraction form
    492.90/679.86 = 318.30/x
  3. Step 3: Cross multiply
    492.90x = 679.86 × 318.30
  4. Step 4: Simplify right side
    492.90x = 216,399.44
  5. Step 5: Solve for x
    x = 216,399.44/492.90
  6. Step 6: Final answer
    x = 439.03

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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.