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Finding the Fourth Proportional to 642.98, 887.19 and 380.87

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Solution

The fourth proportional to 642.98, 887.19 and 380.87 is: 525.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.98 : 887.19 = 380.87 : x
  2. Step 2: Convert to fraction form
    642.98/887.19 = 380.87/x
  3. Step 3: Cross multiply
    642.98x = 887.19 × 380.87
  4. Step 4: Simplify right side
    642.98x = 337,904.06
  5. Step 5: Solve for x
    x = 337,904.06/642.98
  6. Step 6: Final answer
    x = 525.53

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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.