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Finding the Fourth Proportional to 930, 1,285.80 and 889.20

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Solution

The fourth proportional to 930, 1,285.80 and 889.20 is: 1,229.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    930 : 1,285.80 = 889.20 : x
  2. Step 2: Convert to fraction form
    930/1,285.80 = 889.20/x
  3. Step 3: Cross multiply
    930x = 1,285.80 × 889.20
  4. Step 4: Simplify right side
    930x = 1,143,333.36
  5. Step 5: Solve for x
    x = 1,143,333.36/930
  6. Step 6: Final answer
    x = 1,229.39

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.