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Finding the Fourth Proportional to 304.80, 420.78 and 216.30

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Solution

The fourth proportional to 304.80, 420.78 and 216.30 is: 298.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    304.80 : 420.78 = 216.30 : x
  2. Step 2: Convert to fraction form
    304.80/420.78 = 216.30/x
  3. Step 3: Cross multiply
    304.80x = 420.78 × 216.30
  4. Step 4: Simplify right side
    304.80x = 91,014.71
  5. Step 5: Solve for x
    x = 91,014.71/304.80
  6. Step 6: Final answer
    x = 298.60

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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.