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Finding the Fourth Proportional to 1,285.80, 1,930.20 and 670.20

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Solution

The fourth proportional to 1,285.80, 1,930.20 and 670.20 is: 1,006.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,285.80 : 1,930.20 = 670.20 : x
  2. Step 2: Convert to fraction form
    1,285.80/1,930.20 = 670.20/x
  3. Step 3: Cross multiply
    1,285.80x = 1,930.20 × 670.20
  4. Step 4: Simplify right side
    1,285.80x = 1,293,620.04
  5. Step 5: Solve for x
    x = 1,293,620.04/1,285.80
  6. Step 6: Final answer
    x = 1,006.08

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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.