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Finding the Fourth Proportional to 678.15, 1,018.84 and 435.15

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Solution

The fourth proportional to 678.15, 1,018.84 and 435.15 is: 653.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.15 : 1,018.84 = 435.15 : x
  2. Step 2: Convert to fraction form
    678.15/1,018.84 = 435.15/x
  3. Step 3: Cross multiply
    678.15x = 1,018.84 × 435.15
  4. Step 4: Simplify right side
    678.15x = 443,342.04
  5. Step 5: Solve for x
    x = 443,342.04/678.15
  6. Step 6: Final answer
    x = 653.76

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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.