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Finding the Fourth Proportional to 642.70, 887.16 and 380.98

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Solution

The fourth proportional to 642.70, 887.16 and 380.98 is: 525.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.70 : 887.16 = 380.98 : x
  2. Step 2: Convert to fraction form
    642.70/887.16 = 380.98/x
  3. Step 3: Cross multiply
    642.70x = 887.16 × 380.98
  4. Step 4: Simplify right side
    642.70x = 337,990.22
  5. Step 5: Solve for x
    x = 337,990.22/642.70
  6. Step 6: Final answer
    x = 525.89

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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.