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Finding the Fourth Proportional to 642.70, 965.42 and 545.40

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Solution

The fourth proportional to 642.70, 965.42 and 545.40 is: 819.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.70 : 965.42 = 545.40 : x
  2. Step 2: Convert to fraction form
    642.70/965.42 = 545.40/x
  3. Step 3: Cross multiply
    642.70x = 965.42 × 545.40
  4. Step 4: Simplify right side
    642.70x = 526,540.07
  5. Step 5: Solve for x
    x = 526,540.07/642.70
  6. Step 6: Final answer
    x = 819.26

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.