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Finding the Fourth Proportional to 280.08, 420.15 and 74.65

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Solution

The fourth proportional to 280.08, 420.15 and 74.65 is: 111.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.08 : 420.15 = 74.65 : x
  2. Step 2: Convert to fraction form
    280.08/420.15 = 74.65/x
  3. Step 3: Cross multiply
    280.08x = 420.15 × 74.65
  4. Step 4: Simplify right side
    280.08x = 31,362.40
  5. Step 5: Solve for x
    x = 31,362.40/280.08
  6. Step 6: Final answer
    x = 111.98

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.