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Finding the Fourth Proportional to 645.60, 889.20 and 521.04

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Solution

The fourth proportional to 645.60, 889.20 and 521.04 is: 717.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.60 : 889.20 = 521.04 : x
  2. Step 2: Convert to fraction form
    645.60/889.20 = 521.04/x
  3. Step 3: Cross multiply
    645.60x = 889.20 × 521.04
  4. Step 4: Simplify right side
    645.60x = 463,308.77
  5. Step 5: Solve for x
    x = 463,308.77/645.60
  6. Step 6: Final answer
    x = 717.64

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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.