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Finding the Fourth Proportional to 818.61, 1,129.80 and 487.06

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Solution

The fourth proportional to 818.61, 1,129.80 and 487.06 is: 672.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.61 : 1,129.80 = 487.06 : x
  2. Step 2: Convert to fraction form
    818.61/1,129.80 = 487.06/x
  3. Step 3: Cross multiply
    818.61x = 1,129.80 × 487.06
  4. Step 4: Simplify right side
    818.61x = 550,283.01
  5. Step 5: Solve for x
    x = 550,283.01/818.61
  6. Step 6: Final answer
    x = 672.22

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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.