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Finding the Fourth Proportional to 430.85, 644.90 and 308.75

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Solution

The fourth proportional to 430.85, 644.90 and 308.75 is: 462.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.85 : 644.90 = 308.75 : x
  2. Step 2: Convert to fraction form
    430.85/644.90 = 308.75/x
  3. Step 3: Cross multiply
    430.85x = 644.90 × 308.75
  4. Step 4: Simplify right side
    430.85x = 199,108.11
  5. Step 5: Solve for x
    x = 199,108.11/430.85
  6. Step 6: Final answer
    x = 462.13

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.