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Finding the Fourth Proportional to 865.86, 1,297.89 and 648.78

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Solution

The fourth proportional to 865.86, 1,297.89 and 648.78 is: 972.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.86 : 1,297.89 = 648.78 : x
  2. Step 2: Convert to fraction form
    865.86/1,297.89 = 648.78/x
  3. Step 3: Cross multiply
    865.86x = 1,297.89 × 648.78
  4. Step 4: Simplify right side
    865.86x = 842,045.07
  5. Step 5: Solve for x
    x = 842,045.07/865.86
  6. Step 6: Final answer
    x = 972.50

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.