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Finding the Fourth Proportional to 642.60, 874.80 and 642.60

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Solution

The fourth proportional to 642.60, 874.80 and 642.60 is: 874.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.60 : 874.80 = 642.60 : x
  2. Step 2: Convert to fraction form
    642.60/874.80 = 642.60/x
  3. Step 3: Cross multiply
    642.60x = 874.80 × 642.60
  4. Step 4: Simplify right side
    642.60x = 562,146.48
  5. Step 5: Solve for x
    x = 562,146.48/642.60
  6. Step 6: Final answer
    x = 874.80

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Why These Related Problems?

These problems maintain the same ratio (1.36) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.