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Finding the Fourth Proportional to 815.33, 1,123.84 and 638.00

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Solution

The fourth proportional to 815.33, 1,123.84 and 638.00 is: 879.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.33 : 1,123.84 = 638.00 : x
  2. Step 2: Convert to fraction form
    815.33/1,123.84 = 638.00/x
  3. Step 3: Cross multiply
    815.33x = 1,123.84 × 638.00
  4. Step 4: Simplify right side
    815.33x = 717,005.72
  5. Step 5: Solve for x
    x = 717,005.72/815.33
  6. Step 6: Final answer
    x = 879.40

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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.