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Finding the Fourth Proportional to 1,289.60, 1,932.84 and 638.80

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Solution

The fourth proportional to 1,289.60, 1,932.84 and 638.80 is: 957.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,289.60 : 1,932.84 = 638.80 : x
  2. Step 2: Convert to fraction form
    1,289.60/1,932.84 = 638.80/x
  3. Step 3: Cross multiply
    1,289.60x = 1,932.84 × 638.80
  4. Step 4: Simplify right side
    1,289.60x = 1,234,698.19
  5. Step 5: Solve for x
    x = 1,234,698.19/1,289.60
  6. Step 6: Final answer
    x = 957.43

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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.