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Finding the Fourth Proportional to 810.30, 1,215.45 and 579.90

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Solution

The fourth proportional to 810.30, 1,215.45 and 579.90 is: 869.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.30 : 1,215.45 = 579.90 : x
  2. Step 2: Convert to fraction form
    810.30/1,215.45 = 579.90/x
  3. Step 3: Cross multiply
    810.30x = 1,215.45 × 579.90
  4. Step 4: Simplify right side
    810.30x = 704,839.46
  5. Step 5: Solve for x
    x = 704,839.46/810.30
  6. Step 6: Final answer
    x = 869.85

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Double scale
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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.