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Finding the Fourth Proportional to 642.40, 888.24 and 560.39

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Solution

The fourth proportional to 642.40, 888.24 and 560.39 is: 774.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.40 : 888.24 = 560.39 : x
  2. Step 2: Convert to fraction form
    642.40/888.24 = 560.39/x
  3. Step 3: Cross multiply
    642.40x = 888.24 × 560.39
  4. Step 4: Simplify right side
    642.40x = 497,760.81
  5. Step 5: Solve for x
    x = 497,760.81/642.40
  6. Step 6: Final answer
    x = 774.85

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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.