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Finding the Fourth Proportional to 810.61, 1,216.82 and 445.70

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Solution

The fourth proportional to 810.61, 1,216.82 and 445.70 is: 669.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.61 : 1,216.82 = 445.70 : x
  2. Step 2: Convert to fraction form
    810.61/1,216.82 = 445.70/x
  3. Step 3: Cross multiply
    810.61x = 1,216.82 × 445.70
  4. Step 4: Simplify right side
    810.61x = 542,340.83
  5. Step 5: Solve for x
    x = 542,340.83/810.61
  6. Step 6: Final answer
    x = 669.05

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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.