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Finding the Fourth Proportional to 491.68, 678.56 and 284.80

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Solution

The fourth proportional to 491.68, 678.56 and 284.80 is: 393.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.68 : 678.56 = 284.80 : x
  2. Step 2: Convert to fraction form
    491.68/678.56 = 284.80/x
  3. Step 3: Cross multiply
    491.68x = 678.56 × 284.80
  4. Step 4: Simplify right side
    491.68x = 193,253.89
  5. Step 5: Solve for x
    x = 193,253.89/491.68
  6. Step 6: Final answer
    x = 393.05

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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.