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Finding the Fourth Proportional to 420.45, 630.74 and 189.34

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Solution

The fourth proportional to 420.45, 630.74 and 189.34 is: 284.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.45 : 630.74 = 189.34 : x
  2. Step 2: Convert to fraction form
    420.45/630.74 = 189.34/x
  3. Step 3: Cross multiply
    420.45x = 630.74 × 189.34
  4. Step 4: Simplify right side
    420.45x = 119,424.31
  5. Step 5: Solve for x
    x = 119,424.31/420.45
  6. Step 6: Final answer
    x = 284.04

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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.