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Finding the Fourth Proportional to 971.78, 1,341.13 and 557.78

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Solution

The fourth proportional to 971.78, 1,341.13 and 557.78 is: 769.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    971.78 : 1,341.13 = 557.78 : x
  2. Step 2: Convert to fraction form
    971.78/1,341.13 = 557.78/x
  3. Step 3: Cross multiply
    971.78x = 1,341.13 × 557.78
  4. Step 4: Simplify right side
    971.78x = 748,055.49
  5. Step 5: Solve for x
    x = 748,055.49/971.78
  6. Step 6: Final answer
    x = 769.78

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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.