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Finding the Fourth Proportional to 742.30, 1,115.10 and 620.80

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Solution

The fourth proportional to 742.30, 1,115.10 and 620.80 is: 932.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    742.30 : 1,115.10 = 620.80 : x
  2. Step 2: Convert to fraction form
    742.30/1,115.10 = 620.80/x
  3. Step 3: Cross multiply
    742.30x = 1,115.10 × 620.80
  4. Step 4: Simplify right side
    742.30x = 692,254.08
  5. Step 5: Solve for x
    x = 692,254.08/742.30
  6. Step 6: Final answer
    x = 932.58

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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.