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Finding the Fourth Proportional to 1,280.60, 1,920.45 and 458.90

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Solution

The fourth proportional to 1,280.60, 1,920.45 and 458.90 is: 688.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.60 : 1,920.45 = 458.90 : x
  2. Step 2: Convert to fraction form
    1,280.60/1,920.45 = 458.90/x
  3. Step 3: Cross multiply
    1,280.60x = 1,920.45 × 458.90
  4. Step 4: Simplify right side
    1,280.60x = 881,294.51
  5. Step 5: Solve for x
    x = 881,294.51/1,280.60
  6. Step 6: Final answer
    x = 688.19

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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.