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Finding the Fourth Proportional to 815.08, 1,124.58 and 639.88

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Solution

The fourth proportional to 815.08, 1,124.58 and 639.88 is: 882.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.08 : 1,124.58 = 639.88 : x
  2. Step 2: Convert to fraction form
    815.08/1,124.58 = 639.88/x
  3. Step 3: Cross multiply
    815.08x = 1,124.58 × 639.88
  4. Step 4: Simplify right side
    815.08x = 719,596.25
  5. Step 5: Solve for x
    x = 719,596.25/815.08
  6. Step 6: Final answer
    x = 882.85

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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.