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Finding the Fourth Proportional to 307.40, 423.78 and 280.04

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Solution

The fourth proportional to 307.40, 423.78 and 280.04 is: 386.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    307.40 : 423.78 = 280.04 : x
  2. Step 2: Convert to fraction form
    307.40/423.78 = 280.04/x
  3. Step 3: Cross multiply
    307.40x = 423.78 × 280.04
  4. Step 4: Simplify right side
    307.40x = 118,675.35
  5. Step 5: Solve for x
    x = 118,675.35/307.40
  6. Step 6: Final answer
    x = 386.06

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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.