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Finding the Fourth Proportional to 1,388.68, 2,081.80 and 522.80

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Solution

The fourth proportional to 1,388.68, 2,081.80 and 522.80 is: 783.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,388.68 : 2,081.80 = 522.80 : x
  2. Step 2: Convert to fraction form
    1,388.68/2,081.80 = 522.80/x
  3. Step 3: Cross multiply
    1,388.68x = 2,081.80 × 522.80
  4. Step 4: Simplify right side
    1,388.68x = 1,088,365.04
  5. Step 5: Solve for x
    x = 1,088,365.04/1,388.68
  6. Step 6: Final answer
    x = 783.74

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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.