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Finding the Fourth Proportional to 640, 883.20 and 407.56

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Solution

The fourth proportional to 640, 883.20 and 407.56 is: 562.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    640 : 883.20 = 407.56 : x
  2. Step 2: Convert to fraction form
    640/883.20 = 407.56/x
  3. Step 3: Cross multiply
    640x = 883.20 × 407.56
  4. Step 4: Simplify right side
    640x = 359,956.99
  5. Step 5: Solve for x
    x = 359,956.99/640
  6. Step 6: Final answer
    x = 562.43

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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.