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Finding the Fourth Proportional to 280.45, 386.91 and 187.15

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Solution

The fourth proportional to 280.45, 386.91 and 187.15 is: 258.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.45 : 386.91 = 187.15 : x
  2. Step 2: Convert to fraction form
    280.45/386.91 = 187.15/x
  3. Step 3: Cross multiply
    280.45x = 386.91 × 187.15
  4. Step 4: Simplify right side
    280.45x = 72,410.21
  5. Step 5: Solve for x
    x = 72,410.21/280.45
  6. Step 6: Final answer
    x = 258.19

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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.