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Finding the Fourth Proportional to 678.38, 934.80 and 491.54

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Solution

The fourth proportional to 678.38, 934.80 and 491.54 is: 677.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.38 : 934.80 = 491.54 : x
  2. Step 2: Convert to fraction form
    678.38/934.80 = 491.54/x
  3. Step 3: Cross multiply
    678.38x = 934.80 × 491.54
  4. Step 4: Simplify right side
    678.38x = 459,491.59
  5. Step 5: Solve for x
    x = 459,491.59/678.38
  6. Step 6: Final answer
    x = 677.34

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Double scale
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1.5x scale

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.