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Finding the Fourth Proportional to 678.78, 935.06 and 491.72

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Solution

The fourth proportional to 678.78, 935.06 and 491.72 is: 677.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.78 : 935.06 = 491.72 : x
  2. Step 2: Convert to fraction form
    678.78/935.06 = 491.72/x
  3. Step 3: Cross multiply
    678.78x = 935.06 × 491.72
  4. Step 4: Simplify right side
    678.78x = 459,780.57
  5. Step 5: Solve for x
    x = 459,780.57/678.78
  6. Step 6: Final answer
    x = 677.36

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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.