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Finding the Fourth Proportional to 3,280.80, 4,921.20 and 972

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Solution

The fourth proportional to 3,280.80, 4,921.20 and 972 is: 1,458.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    3,280.80 : 4,921.20 = 972 : x
  2. Step 2: Convert to fraction form
    3,280.80/4,921.20 = 972/x
  3. Step 3: Cross multiply
    3,280.80x = 4,921.20 × 972
  4. Step 4: Simplify right side
    3,280.80x = 4,783,406.40
  5. Step 5: Solve for x
    x = 4,783,406.40/3,280.80
  6. Step 6: Final answer
    x = 1,458.00

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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.