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Finding the Fourth Proportional to 815.18, 1,124.88 and 638.30

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Solution

The fourth proportional to 815.18, 1,124.88 and 638.30 is: 880.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.18 : 1,124.88 = 638.30 : x
  2. Step 2: Convert to fraction form
    815.18/1,124.88 = 638.30/x
  3. Step 3: Cross multiply
    815.18x = 1,124.88 × 638.30
  4. Step 4: Simplify right side
    815.18x = 718,010.90
  5. Step 5: Solve for x
    x = 718,010.90/815.18
  6. Step 6: Final answer
    x = 880.80

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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.