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Finding the Fourth Proportional to 812.75, 1,218.58 and 402.15

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Solution

The fourth proportional to 812.75, 1,218.58 and 402.15 is: 602.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.75 : 1,218.58 = 402.15 : x
  2. Step 2: Convert to fraction form
    812.75/1,218.58 = 402.15/x
  3. Step 3: Cross multiply
    812.75x = 1,218.58 × 402.15
  4. Step 4: Simplify right side
    812.75x = 490,051.95
  5. Step 5: Solve for x
    x = 490,051.95/812.75
  6. Step 6: Final answer
    x = 602.96

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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.