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Finding the Fourth Proportional to 1,287.30, 1,930.94 and 313.41

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Solution

The fourth proportional to 1,287.30, 1,930.94 and 313.41 is: 470.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,287.30 : 1,930.94 = 313.41 : x
  2. Step 2: Convert to fraction form
    1,287.30/1,930.94 = 313.41/x
  3. Step 3: Cross multiply
    1,287.30x = 1,930.94 × 313.41
  4. Step 4: Simplify right side
    1,287.30x = 605,174.34
  5. Step 5: Solve for x
    x = 605,174.34/1,287.30
  6. Step 6: Final answer
    x = 470.11

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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.