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Finding the Fourth Proportional to 1,288.28, 1,778.49 and 870.81

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Solution

The fourth proportional to 1,288.28, 1,778.49 and 870.81 is: 1,202.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,288.28 : 1,778.49 = 870.81 : x
  2. Step 2: Convert to fraction form
    1,288.28/1,778.49 = 870.81/x
  3. Step 3: Cross multiply
    1,288.28x = 1,778.49 × 870.81
  4. Step 4: Simplify right side
    1,288.28x = 1,548,726.88
  5. Step 5: Solve for x
    x = 1,548,726.88/1,288.28
  6. Step 6: Final answer
    x = 1,202.17

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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.