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Finding the Fourth Proportional to 1,115.05, 1,538.28 and 783.69

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Solution

The fourth proportional to 1,115.05, 1,538.28 and 783.69 is: 1,081.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,115.05 : 1,538.28 = 783.69 : x
  2. Step 2: Convert to fraction form
    1,115.05/1,538.28 = 783.69/x
  3. Step 3: Cross multiply
    1,115.05x = 1,538.28 × 783.69
  4. Step 4: Simplify right side
    1,115.05x = 1,205,534.58
  5. Step 5: Solve for x
    x = 1,205,534.58/1,115.05
  6. Step 6: Final answer
    x = 1,081.15

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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.