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Finding the Fourth Proportional to 678.40, 934.80 and 560.80

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Solution

The fourth proportional to 678.40, 934.80 and 560.80 is: 772.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.40 : 934.80 = 560.80 : x
  2. Step 2: Convert to fraction form
    678.40/934.80 = 560.80/x
  3. Step 3: Cross multiply
    678.40x = 934.80 × 560.80
  4. Step 4: Simplify right side
    678.40x = 524,235.84
  5. Step 5: Solve for x
    x = 524,235.84/678.40
  6. Step 6: Final answer
    x = 772.75

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.