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Finding the Fourth Proportional to 1,320.47, 1,980.75 and 454.78

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Solution

The fourth proportional to 1,320.47, 1,980.75 and 454.78 is: 682.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,320.47 : 1,980.75 = 454.78 : x
  2. Step 2: Convert to fraction form
    1,320.47/1,980.75 = 454.78/x
  3. Step 3: Cross multiply
    1,320.47x = 1,980.75 × 454.78
  4. Step 4: Simplify right side
    1,320.47x = 900,809.67
  5. Step 5: Solve for x
    x = 900,809.67/1,320.47
  6. Step 6: Final answer
    x = 682.19

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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.