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Finding the Fourth Proportional to 859.26, 1,185 and 638.76

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Solution

The fourth proportional to 859.26, 1,185 and 638.76 is: 880.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.26 : 1,185 = 638.76 : x
  2. Step 2: Convert to fraction form
    859.26/1,185 = 638.76/x
  3. Step 3: Cross multiply
    859.26x = 1,185 × 638.76
  4. Step 4: Simplify right side
    859.26x = 756,930.60
  5. Step 5: Solve for x
    x = 756,930.60/859.26
  6. Step 6: Final answer
    x = 880.91

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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.