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Finding the Fourth Proportional to 818.28, 1,128.45 and 631.47

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Solution

The fourth proportional to 818.28, 1,128.45 and 631.47 is: 870.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.28 : 1,128.45 = 631.47 : x
  2. Step 2: Convert to fraction form
    818.28/1,128.45 = 631.47/x
  3. Step 3: Cross multiply
    818.28x = 1,128.45 × 631.47
  4. Step 4: Simplify right side
    818.28x = 712,582.32
  5. Step 5: Solve for x
    x = 712,582.32/818.28
  6. Step 6: Final answer
    x = 870.83

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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.