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Finding the Fourth Proportional to 645.55, 969.12 and 642.59

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Solution

The fourth proportional to 645.55, 969.12 and 642.59 is: 964.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.55 : 969.12 = 642.59 : x
  2. Step 2: Convert to fraction form
    645.55/969.12 = 642.59/x
  3. Step 3: Cross multiply
    645.55x = 969.12 × 642.59
  4. Step 4: Simplify right side
    645.55x = 622,741.98
  5. Step 5: Solve for x
    x = 622,741.98/645.55
  6. Step 6: Final answer
    x = 964.68

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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.