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Finding the Fourth Proportional to 1,388.34, 2,081.70 and 810

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Solution

The fourth proportional to 1,388.34, 2,081.70 and 810 is: 1,214.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,388.34 : 2,081.70 = 810 : x
  2. Step 2: Convert to fraction form
    1,388.34/2,081.70 = 810/x
  3. Step 3: Cross multiply
    1,388.34x = 2,081.70 × 810
  4. Step 4: Simplify right side
    1,388.34x = 1,686,177.00
  5. Step 5: Solve for x
    x = 1,686,177.00/1,388.34
  6. Step 6: Final answer
    x = 1,214.53

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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.