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Finding the Fourth Proportional to 1,320.39, 1,980.80 and 454.50

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Solution

The fourth proportional to 1,320.39, 1,980.80 and 454.50 is: 681.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,320.39 : 1,980.80 = 454.50 : x
  2. Step 2: Convert to fraction form
    1,320.39/1,980.80 = 454.50/x
  3. Step 3: Cross multiply
    1,320.39x = 1,980.80 × 454.50
  4. Step 4: Simplify right side
    1,320.39x = 900,271.33
  5. Step 5: Solve for x
    x = 900,271.33/1,320.39
  6. Step 6: Final answer
    x = 681.82

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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.