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Finding the Fourth Proportional to 678.30, 1,017.45 and 191.35

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Solution

The fourth proportional to 678.30, 1,017.45 and 191.35 is: 287.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.30 : 1,017.45 = 191.35 : x
  2. Step 2: Convert to fraction form
    678.30/1,017.45 = 191.35/x
  3. Step 3: Cross multiply
    678.30x = 1,017.45 × 191.35
  4. Step 4: Simplify right side
    678.30x = 194,689.06
  5. Step 5: Solve for x
    x = 194,689.06/678.30
  6. Step 6: Final answer
    x = 287.03

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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.