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Finding the Fourth Proportional to 920.45, 1,379 and 645.56

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Solution

The fourth proportional to 920.45, 1,379 and 645.56 is: 967.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.45 : 1,379 = 645.56 : x
  2. Step 2: Convert to fraction form
    920.45/1,379 = 645.56/x
  3. Step 3: Cross multiply
    920.45x = 1,379 × 645.56
  4. Step 4: Simplify right side
    920.45x = 890,227.24
  5. Step 5: Solve for x
    x = 890,227.24/920.45
  6. Step 6: Final answer
    x = 967.17

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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.