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Finding the Fourth Proportional to 491.96, 678.89 and 305.46

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Solution

The fourth proportional to 491.96, 678.89 and 305.46 is: 421.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.96 : 678.89 = 305.46 : x
  2. Step 2: Convert to fraction form
    491.96/678.89 = 305.46/x
  3. Step 3: Cross multiply
    491.96x = 678.89 × 305.46
  4. Step 4: Simplify right side
    491.96x = 207,373.74
  5. Step 5: Solve for x
    x = 207,373.74/491.96
  6. Step 6: Final answer
    x = 421.53

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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.