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Finding the Fourth Proportional to 1,319.31, 1,978.98 and 345.51

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Solution

The fourth proportional to 1,319.31, 1,978.98 and 345.51 is: 518.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,319.31 : 1,978.98 = 345.51 : x
  2. Step 2: Convert to fraction form
    1,319.31/1,978.98 = 345.51/x
  3. Step 3: Cross multiply
    1,319.31x = 1,978.98 × 345.51
  4. Step 4: Simplify right side
    1,319.31x = 683,757.38
  5. Step 5: Solve for x
    x = 683,757.38/1,319.31
  6. Step 6: Final answer
    x = 518.27

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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.