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Finding the Fourth Proportional to 642.90, 888.90 and 587.55

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Solution

The fourth proportional to 642.90, 888.90 and 587.55 is: 812.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.90 : 888.90 = 587.55 : x
  2. Step 2: Convert to fraction form
    642.90/888.90 = 587.55/x
  3. Step 3: Cross multiply
    642.90x = 888.90 × 587.55
  4. Step 4: Simplify right side
    642.90x = 522,273.20
  5. Step 5: Solve for x
    x = 522,273.20/642.90
  6. Step 6: Final answer
    x = 812.37

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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.