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Finding the Fourth Proportional to 678.39, 1,017.55 and 191.44

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Solution

The fourth proportional to 678.39, 1,017.55 and 191.44 is: 287.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.39 : 1,017.55 = 191.44 : x
  2. Step 2: Convert to fraction form
    678.39/1,017.55 = 191.44/x
  3. Step 3: Cross multiply
    678.39x = 1,017.55 × 191.44
  4. Step 4: Simplify right side
    678.39x = 194,799.77
  5. Step 5: Solve for x
    x = 194,799.77/678.39
  6. Step 6: Final answer
    x = 287.15

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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.