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Finding the Fourth Proportional to 420.15, 630.30 and 203.74

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Solution

The fourth proportional to 420.15, 630.30 and 203.74 is: 305.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.15 : 630.30 = 203.74 : x
  2. Step 2: Convert to fraction form
    420.15/630.30 = 203.74/x
  3. Step 3: Cross multiply
    420.15x = 630.30 × 203.74
  4. Step 4: Simplify right side
    420.15x = 128,417.32
  5. Step 5: Solve for x
    x = 128,417.32/420.15
  6. Step 6: Final answer
    x = 305.65

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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.