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Finding the Fourth Proportional to 1,253.40, 1,879.50 and 387.72

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Solution

The fourth proportional to 1,253.40, 1,879.50 and 387.72 is: 581.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,253.40 : 1,879.50 = 387.72 : x
  2. Step 2: Convert to fraction form
    1,253.40/1,879.50 = 387.72/x
  3. Step 3: Cross multiply
    1,253.40x = 1,879.50 × 387.72
  4. Step 4: Simplify right side
    1,253.40x = 728,719.74
  5. Step 5: Solve for x
    x = 728,719.74/1,253.40
  6. Step 6: Final answer
    x = 581.39

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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.