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Finding the Fourth Proportional to 815.31, 1,123.80 and 637.97

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Solution

The fourth proportional to 815.31, 1,123.80 and 637.97 is: 879.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.31 : 1,123.80 = 637.97 : x
  2. Step 2: Convert to fraction form
    815.31/1,123.80 = 637.97/x
  3. Step 3: Cross multiply
    815.31x = 1,123.80 × 637.97
  4. Step 4: Simplify right side
    815.31x = 716,945.07
  5. Step 5: Solve for x
    x = 716,945.07/815.31
  6. Step 6: Final answer
    x = 879.35

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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.