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Finding the Fourth Proportional to 649.76, 972.32 and 640

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Solution

The fourth proportional to 649.76, 972.32 and 640 is: 957.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    649.76 : 972.32 = 640 : x
  2. Step 2: Convert to fraction form
    649.76/972.32 = 640/x
  3. Step 3: Cross multiply
    649.76x = 972.32 × 640
  4. Step 4: Simplify right side
    649.76x = 622,284.80
  5. Step 5: Solve for x
    x = 622,284.80/649.76
  6. Step 6: Final answer
    x = 957.71

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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.