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Finding the Fourth Proportional to 865.16, 1,297.75 and 309.90

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Solution

The fourth proportional to 865.16, 1,297.75 and 309.90 is: 464.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.16 : 1,297.75 = 309.90 : x
  2. Step 2: Convert to fraction form
    865.16/1,297.75 = 309.90/x
  3. Step 3: Cross multiply
    865.16x = 1,297.75 × 309.90
  4. Step 4: Simplify right side
    865.16x = 402,177.38
  5. Step 5: Solve for x
    x = 402,177.38/865.16
  6. Step 6: Final answer
    x = 464.86

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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.