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Finding the Fourth Proportional to 818.29, 1,128.47 and 631.48

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Solution

The fourth proportional to 818.29, 1,128.47 and 631.48 is: 870.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.29 : 1,128.47 = 631.48 : x
  2. Step 2: Convert to fraction form
    818.29/1,128.47 = 631.48/x
  3. Step 3: Cross multiply
    818.29x = 1,128.47 × 631.48
  4. Step 4: Simplify right side
    818.29x = 712,606.24
  5. Step 5: Solve for x
    x = 712,606.24/818.29
  6. Step 6: Final answer
    x = 870.85

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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.