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Finding the Fourth Proportional to 920.99, 1,380.42 and 459.09

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Solution

The fourth proportional to 920.99, 1,380.42 and 459.09 is: 688.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.99 : 1,380.42 = 459.09 : x
  2. Step 2: Convert to fraction form
    920.99/1,380.42 = 459.09/x
  3. Step 3: Cross multiply
    920.99x = 1,380.42 × 459.09
  4. Step 4: Simplify right side
    920.99x = 633,737.02
  5. Step 5: Solve for x
    x = 633,737.02/920.99
  6. Step 6: Final answer
    x = 688.11

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1.5x scale

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.