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Finding the Fourth Proportional to 742.90, 1,025.29 and 428.18

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Solution

The fourth proportional to 742.90, 1,025.29 and 428.18 is: 590.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    742.90 : 1,025.29 = 428.18 : x
  2. Step 2: Convert to fraction form
    742.90/1,025.29 = 428.18/x
  3. Step 3: Cross multiply
    742.90x = 1,025.29 × 428.18
  4. Step 4: Simplify right side
    742.90x = 439,008.67
  5. Step 5: Solve for x
    x = 439,008.67/742.90
  6. Step 6: Final answer
    x = 590.94

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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.