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Finding the Fourth Proportional to 1,115.64, 1,540.53 and 784.80

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Solution

The fourth proportional to 1,115.64, 1,540.53 and 784.80 is: 1,083.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,115.64 : 1,540.53 = 784.80 : x
  2. Step 2: Convert to fraction form
    1,115.64/1,540.53 = 784.80/x
  3. Step 3: Cross multiply
    1,115.64x = 1,540.53 × 784.80
  4. Step 4: Simplify right side
    1,115.64x = 1,209,007.94
  5. Step 5: Solve for x
    x = 1,209,007.94/1,115.64
  6. Step 6: Final answer
    x = 1,083.69

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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.