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Finding the Fourth Proportional to 889.20, 1,331.76 and 645

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Solution

The fourth proportional to 889.20, 1,331.76 and 645 is: 966.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    889.20 : 1,331.76 = 645 : x
  2. Step 2: Convert to fraction form
    889.20/1,331.76 = 645/x
  3. Step 3: Cross multiply
    889.20x = 1,331.76 × 645
  4. Step 4: Simplify right side
    889.20x = 858,985.20
  5. Step 5: Solve for x
    x = 858,985.20/889.20
  6. Step 6: Final answer
    x = 966.02

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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.