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Finding the Fourth Proportional to 1,320.20, 1,980.08 and 580.13

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Solution

The fourth proportional to 1,320.20, 1,980.08 and 580.13 is: 870.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,320.20 : 1,980.08 = 580.13 : x
  2. Step 2: Convert to fraction form
    1,320.20/1,980.08 = 580.13/x
  3. Step 3: Cross multiply
    1,320.20x = 1,980.08 × 580.13
  4. Step 4: Simplify right side
    1,320.20x = 1,148,703.81
  5. Step 5: Solve for x
    x = 1,148,703.81/1,320.20
  6. Step 6: Final answer
    x = 870.10

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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.