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Finding the Fourth Proportional to 642.31, 887.30 and 511.15

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Solution

The fourth proportional to 642.31, 887.30 and 511.15 is: 706.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.31 : 887.30 = 511.15 : x
  2. Step 2: Convert to fraction form
    642.31/887.30 = 511.15/x
  3. Step 3: Cross multiply
    642.31x = 887.30 × 511.15
  4. Step 4: Simplify right side
    642.31x = 453,540.84
  5. Step 5: Solve for x
    x = 453,540.84/642.31
  6. Step 6: Final answer
    x = 706.11

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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.