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Finding the Fourth Proportional to 658.87, 989.72 and 640.64

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Solution

The fourth proportional to 658.87, 989.72 and 640.64 is: 962.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    658.87 : 989.72 = 640.64 : x
  2. Step 2: Convert to fraction form
    658.87/989.72 = 640.64/x
  3. Step 3: Cross multiply
    658.87x = 989.72 × 640.64
  4. Step 4: Simplify right side
    658.87x = 634,054.22
  5. Step 5: Solve for x
    x = 634,054.22/658.87
  6. Step 6: Final answer
    x = 962.34

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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.