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Finding the Fourth Proportional to 1,280.79, 1,921.44 and 458.85

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Solution

The fourth proportional to 1,280.79, 1,921.44 and 458.85 is: 688.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.79 : 1,921.44 = 458.85 : x
  2. Step 2: Convert to fraction form
    1,280.79/1,921.44 = 458.85/x
  3. Step 3: Cross multiply
    1,280.79x = 1,921.44 × 458.85
  4. Step 4: Simplify right side
    1,280.79x = 881,643.14
  5. Step 5: Solve for x
    x = 881,643.14/1,280.79
  6. Step 6: Final answer
    x = 688.36

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1.5x scale

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.