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Finding the Fourth Proportional to 1,288.71, 1,933.20 and 639.27

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Solution

The fourth proportional to 1,288.71, 1,933.20 and 639.27 is: 958.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,288.71 : 1,933.20 = 639.27 : x
  2. Step 2: Convert to fraction form
    1,288.71/1,933.20 = 639.27/x
  3. Step 3: Cross multiply
    1,288.71x = 1,933.20 × 639.27
  4. Step 4: Simplify right side
    1,288.71x = 1,235,836.76
  5. Step 5: Solve for x
    x = 1,235,836.76/1,288.71
  6. Step 6: Final answer
    x = 958.97

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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.