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Finding the Fourth Proportional to 403.40, 556.80 and 279.08

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Solution

The fourth proportional to 403.40, 556.80 and 279.08 is: 385.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    403.40 : 556.80 = 279.08 : x
  2. Step 2: Convert to fraction form
    403.40/556.80 = 279.08/x
  3. Step 3: Cross multiply
    403.40x = 556.80 × 279.08
  4. Step 4: Simplify right side
    403.40x = 155,391.74
  5. Step 5: Solve for x
    x = 155,391.74/403.40
  6. Step 6: Final answer
    x = 385.21

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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.