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Finding the Fourth Proportional to 491.84, 678.88 and 305.36

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Solution

The fourth proportional to 491.84, 678.88 and 305.36 is: 421.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.84 : 678.88 = 305.36 : x
  2. Step 2: Convert to fraction form
    491.84/678.88 = 305.36/x
  3. Step 3: Cross multiply
    491.84x = 678.88 × 305.36
  4. Step 4: Simplify right side
    491.84x = 207,302.80
  5. Step 5: Solve for x
    x = 207,302.80/491.84
  6. Step 6: Final answer
    x = 421.48

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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.