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Finding the Fourth Proportional to 971.49, 1,340.78 and 578.51

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Solution

The fourth proportional to 971.49, 1,340.78 and 578.51 is: 798.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    971.49 : 1,340.78 = 578.51 : x
  2. Step 2: Convert to fraction form
    971.49/1,340.78 = 578.51/x
  3. Step 3: Cross multiply
    971.49x = 1,340.78 × 578.51
  4. Step 4: Simplify right side
    971.49x = 775,654.64
  5. Step 5: Solve for x
    x = 775,654.64/971.49
  6. Step 6: Final answer
    x = 798.42

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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.