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Finding the Fourth Proportional to 678.30, 1,017.10 and 312.77

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Solution

The fourth proportional to 678.30, 1,017.10 and 312.77 is: 468.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.30 : 1,017.10 = 312.77 : x
  2. Step 2: Convert to fraction form
    678.30/1,017.10 = 312.77/x
  3. Step 3: Cross multiply
    678.30x = 1,017.10 × 312.77
  4. Step 4: Simplify right side
    678.30x = 318,118.37
  5. Step 5: Solve for x
    x = 318,118.37/678.30
  6. Step 6: Final answer
    x = 468.99

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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.