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Finding the Fourth Proportional to 813.30, 1,218.76 and 442.79

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Solution

The fourth proportional to 813.30, 1,218.76 and 442.79 is: 663.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.30 : 1,218.76 = 442.79 : x
  2. Step 2: Convert to fraction form
    813.30/1,218.76 = 442.79/x
  3. Step 3: Cross multiply
    813.30x = 1,218.76 × 442.79
  4. Step 4: Simplify right side
    813.30x = 539,654.74
  5. Step 5: Solve for x
    x = 539,654.74/813.30
  6. Step 6: Final answer
    x = 663.54

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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.