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Finding the Fourth Proportional to 920.97, 1,380.38 and 645.57

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Solution

The fourth proportional to 920.97, 1,380.38 and 645.57 is: 967.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.97 : 1,380.38 = 645.57 : x
  2. Step 2: Convert to fraction form
    920.97/1,380.38 = 645.57/x
  3. Step 3: Cross multiply
    920.97x = 1,380.38 × 645.57
  4. Step 4: Simplify right side
    920.97x = 891,128.69
  5. Step 5: Solve for x
    x = 891,128.69/920.97
  6. Step 6: Final answer
    x = 967.60

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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.