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Finding the Fourth Proportional to 1,386.39, 2,079.36 and 508.80

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Solution

The fourth proportional to 1,386.39, 2,079.36 and 508.80 is: 763.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,386.39 : 2,079.36 = 508.80 : x
  2. Step 2: Convert to fraction form
    1,386.39/2,079.36 = 508.80/x
  3. Step 3: Cross multiply
    1,386.39x = 2,079.36 × 508.80
  4. Step 4: Simplify right side
    1,386.39x = 1,057,978.37
  5. Step 5: Solve for x
    x = 1,057,978.37/1,386.39
  6. Step 6: Final answer
    x = 763.12

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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.