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Finding the Fourth Proportional to 1,138.69, 1,569.04 and 784.72

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Solution

The fourth proportional to 1,138.69, 1,569.04 and 784.72 is: 1,081.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,138.69 : 1,569.04 = 784.72 : x
  2. Step 2: Convert to fraction form
    1,138.69/1,569.04 = 784.72/x
  3. Step 3: Cross multiply
    1,138.69x = 1,569.04 × 784.72
  4. Step 4: Simplify right side
    1,138.69x = 1,231,257.07
  5. Step 5: Solve for x
    x = 1,231,257.07/1,138.69
  6. Step 6: Final answer
    x = 1,081.29

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Double scale
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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.