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Finding the Fourth Proportional to 280.40, 386.75 and 187.10

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Solution

The fourth proportional to 280.40, 386.75 and 187.10 is: 258.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.40 : 386.75 = 187.10 : x
  2. Step 2: Convert to fraction form
    280.40/386.75 = 187.10/x
  3. Step 3: Cross multiply
    280.40x = 386.75 × 187.10
  4. Step 4: Simplify right side
    280.40x = 72,359.99
  5. Step 5: Solve for x
    x = 72,359.99/280.40
  6. Step 6: Final answer
    x = 258.06

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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.