Home / 1,320.40-1,980.80-487.52

Finding the Fourth Proportional to 1,320.40, 1,980.80 and 487.52

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Solution

The fourth proportional to 1,320.40, 1,980.80 and 487.52 is: 731.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,320.40 : 1,980.80 = 487.52 : x
  2. Step 2: Convert to fraction form
    1,320.40/1,980.80 = 487.52/x
  3. Step 3: Cross multiply
    1,320.40x = 1,980.80 × 487.52
  4. Step 4: Simplify right side
    1,320.40x = 965,679.62
  5. Step 5: Solve for x
    x = 965,679.62/1,320.40
  6. Step 6: Final answer
    x = 731.35

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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.