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Finding the Fourth Proportional to 1,107, 1,661.76 and 645.12

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Solution

The fourth proportional to 1,107, 1,661.76 and 645.12 is: 968.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,107 : 1,661.76 = 645.12 : x
  2. Step 2: Convert to fraction form
    1,107/1,661.76 = 645.12/x
  3. Step 3: Cross multiply
    1,107x = 1,661.76 × 645.12
  4. Step 4: Simplify right side
    1,107x = 1,072,034.61
  5. Step 5: Solve for x
    x = 1,072,034.61/1,107
  6. Step 6: Final answer
    x = 968.41

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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.