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Finding the Fourth Proportional to 810.80, 1,215.72 and 502.80

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Solution

The fourth proportional to 810.80, 1,215.72 and 502.80 is: 753.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.80 : 1,215.72 = 502.80 : x
  2. Step 2: Convert to fraction form
    810.80/1,215.72 = 502.80/x
  3. Step 3: Cross multiply
    810.80x = 1,215.72 × 502.80
  4. Step 4: Simplify right side
    810.80x = 611,264.02
  5. Step 5: Solve for x
    x = 611,264.02/810.80
  6. Step 6: Final answer
    x = 753.90

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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.