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Finding the Fourth Proportional to 420.16, 630.39 and 203.89

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Solution

The fourth proportional to 420.16, 630.39 and 203.89 is: 305.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.16 : 630.39 = 203.89 : x
  2. Step 2: Convert to fraction form
    420.16/630.39 = 203.89/x
  3. Step 3: Cross multiply
    420.16x = 630.39 × 203.89
  4. Step 4: Simplify right side
    420.16x = 128,530.22
  5. Step 5: Solve for x
    x = 128,530.22/420.16
  6. Step 6: Final answer
    x = 305.91

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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.