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Finding the Fourth Proportional to 810.31, 1,118.28 and 515.65

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Solution

The fourth proportional to 810.31, 1,118.28 and 515.65 is: 711.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.31 : 1,118.28 = 515.65 : x
  2. Step 2: Convert to fraction form
    810.31/1,118.28 = 515.65/x
  3. Step 3: Cross multiply
    810.31x = 1,118.28 × 515.65
  4. Step 4: Simplify right side
    810.31x = 576,641.08
  5. Step 5: Solve for x
    x = 576,641.08/810.31
  6. Step 6: Final answer
    x = 711.63

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.