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Finding the Fourth Proportional to 645.04, 890.40 and 383.20

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Solution

The fourth proportional to 645.04, 890.40 and 383.20 is: 528.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.04 : 890.40 = 383.20 : x
  2. Step 2: Convert to fraction form
    645.04/890.40 = 383.20/x
  3. Step 3: Cross multiply
    645.04x = 890.40 × 383.20
  4. Step 4: Simplify right side
    645.04x = 341,201.28
  5. Step 5: Solve for x
    x = 341,201.28/645.04
  6. Step 6: Final answer
    x = 528.96

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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.