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Finding the Fourth Proportional to 645.07, 959.85 and 642.91

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Solution

The fourth proportional to 645.07, 959.85 and 642.91 is: 956.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.07 : 959.85 = 642.91 : x
  2. Step 2: Convert to fraction form
    645.07/959.85 = 642.91/x
  3. Step 3: Cross multiply
    645.07x = 959.85 × 642.91
  4. Step 4: Simplify right side
    645.07x = 617,097.16
  5. Step 5: Solve for x
    x = 617,097.16/645.07
  6. Step 6: Final answer
    x = 956.64

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.