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Finding the Fourth Proportional to 430.89, 645.99 and 211.42

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Solution

The fourth proportional to 430.89, 645.99 and 211.42 is: 316.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.89 : 645.99 = 211.42 : x
  2. Step 2: Convert to fraction form
    430.89/645.99 = 211.42/x
  3. Step 3: Cross multiply
    430.89x = 645.99 × 211.42
  4. Step 4: Simplify right side
    430.89x = 136,575.21
  5. Step 5: Solve for x
    x = 136,575.21/430.89
  6. Step 6: Final answer
    x = 316.96

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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.