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Finding the Fourth Proportional to 780.11, 1,077.86 and 615.59

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Solution

The fourth proportional to 780.11, 1,077.86 and 615.59 is: 850.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.11 : 1,077.86 = 615.59 : x
  2. Step 2: Convert to fraction form
    780.11/1,077.86 = 615.59/x
  3. Step 3: Cross multiply
    780.11x = 1,077.86 × 615.59
  4. Step 4: Simplify right side
    780.11x = 663,511.37
  5. Step 5: Solve for x
    x = 663,511.37/780.11
  6. Step 6: Final answer
    x = 850.53

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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.