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Finding the Fourth Proportional to 491.79, 678.32 and 314.78

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Solution

The fourth proportional to 491.79, 678.32 and 314.78 is: 434.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.79 : 678.32 = 314.78 : x
  2. Step 2: Convert to fraction form
    491.79/678.32 = 314.78/x
  3. Step 3: Cross multiply
    491.79x = 678.32 × 314.78
  4. Step 4: Simplify right side
    491.79x = 213,516.60
  5. Step 5: Solve for x
    x = 213,516.60/491.79
  6. Step 6: Final answer
    x = 434.16

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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.