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Finding the Fourth Proportional to 420.99, 630.87 and 266.55

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Solution

The fourth proportional to 420.99, 630.87 and 266.55 is: 399.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.99 : 630.87 = 266.55 : x
  2. Step 2: Convert to fraction form
    420.99/630.87 = 266.55/x
  3. Step 3: Cross multiply
    420.99x = 630.87 × 266.55
  4. Step 4: Simplify right side
    420.99x = 168,158.40
  5. Step 5: Solve for x
    x = 168,158.40/420.99
  6. Step 6: Final answer
    x = 399.44

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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.