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Finding the Fourth Proportional to 430.78, 645.99 and 238.18

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Solution

The fourth proportional to 430.78, 645.99 and 238.18 is: 357.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.78 : 645.99 = 238.18 : x
  2. Step 2: Convert to fraction form
    430.78/645.99 = 238.18/x
  3. Step 3: Cross multiply
    430.78x = 645.99 × 238.18
  4. Step 4: Simplify right side
    430.78x = 153,861.90
  5. Step 5: Solve for x
    x = 153,861.90/430.78
  6. Step 6: Final answer
    x = 357.17

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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.