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Finding the Fourth Proportional to 956.96, 1,320.37 and 642.80

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Solution

The fourth proportional to 956.96, 1,320.37 and 642.80 is: 886.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    956.96 : 1,320.37 = 642.80 : x
  2. Step 2: Convert to fraction form
    956.96/1,320.37 = 642.80/x
  3. Step 3: Cross multiply
    956.96x = 1,320.37 × 642.80
  4. Step 4: Simplify right side
    956.96x = 848,735.53
  5. Step 5: Solve for x
    x = 848,735.53/956.96
  6. Step 6: Final answer
    x = 886.90

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.