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Finding the Fourth Proportional to 709.38, 1,064.07 and 678.40

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Solution

The fourth proportional to 709.38, 1,064.07 and 678.40 is: 1,017.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    709.38 : 1,064.07 = 678.40 : x
  2. Step 2: Convert to fraction form
    709.38/1,064.07 = 678.40/x
  3. Step 3: Cross multiply
    709.38x = 1,064.07 × 678.40
  4. Step 4: Simplify right side
    709.38x = 721,862.43
  5. Step 5: Solve for x
    x = 721,862.43/709.38
  6. Step 6: Final answer
    x = 1,017.60

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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.