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Finding the Fourth Proportional to 1,238.78, 1,857.34 and 653.16

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Solution

The fourth proportional to 1,238.78, 1,857.34 and 653.16 is: 979.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,238.78 : 1,857.34 = 653.16 : x
  2. Step 2: Convert to fraction form
    1,238.78/1,857.34 = 653.16/x
  3. Step 3: Cross multiply
    1,238.78x = 1,857.34 × 653.16
  4. Step 4: Simplify right side
    1,238.78x = 1,213,148.89
  5. Step 5: Solve for x
    x = 1,213,148.89/1,238.78
  6. Step 6: Final answer
    x = 979.31

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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.