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Finding the Fourth Proportional to 308.40, 425.50 and 278.80

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Solution

The fourth proportional to 308.40, 425.50 and 278.80 is: 384.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    308.40 : 425.50 = 278.80 : x
  2. Step 2: Convert to fraction form
    308.40/425.50 = 278.80/x
  3. Step 3: Cross multiply
    308.40x = 425.50 × 278.80
  4. Step 4: Simplify right side
    308.40x = 118,629.40
  5. Step 5: Solve for x
    x = 118,629.40/308.40
  6. Step 6: Final answer
    x = 384.66

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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.