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Finding the Fourth Proportional to 815.64, 1,125.72 and 618.78

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Solution

The fourth proportional to 815.64, 1,125.72 and 618.78 is: 854.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.64 : 1,125.72 = 618.78 : x
  2. Step 2: Convert to fraction form
    815.64/1,125.72 = 618.78/x
  3. Step 3: Cross multiply
    815.64x = 1,125.72 × 618.78
  4. Step 4: Simplify right side
    815.64x = 696,573.02
  5. Step 5: Solve for x
    x = 696,573.02/815.64
  6. Step 6: Final answer
    x = 854.02

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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.