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Finding the Fourth Proportional to 420.99, 631.61 and 147.07

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Solution

The fourth proportional to 420.99, 631.61 and 147.07 is: 220.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.99 : 631.61 = 147.07 : x
  2. Step 2: Convert to fraction form
    420.99/631.61 = 147.07/x
  3. Step 3: Cross multiply
    420.99x = 631.61 × 147.07
  4. Step 4: Simplify right side
    420.99x = 92,890.88
  5. Step 5: Solve for x
    x = 92,890.88/420.99
  6. Step 6: Final answer
    x = 220.65

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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.