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Finding the Fourth Proportional to 687.16, 1,023.38 and 645.26

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Solution

The fourth proportional to 687.16, 1,023.38 and 645.26 is: 960.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.16 : 1,023.38 = 645.26 : x
  2. Step 2: Convert to fraction form
    687.16/1,023.38 = 645.26/x
  3. Step 3: Cross multiply
    687.16x = 1,023.38 × 645.26
  4. Step 4: Simplify right side
    687.16x = 660,346.18
  5. Step 5: Solve for x
    x = 660,346.18/687.16
  6. Step 6: Final answer
    x = 960.98

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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.