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Finding the Fourth Proportional to 712.40, 1,068.80 and 279.32

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Solution

The fourth proportional to 712.40, 1,068.80 and 279.32 is: 419.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    712.40 : 1,068.80 = 279.32 : x
  2. Step 2: Convert to fraction form
    712.40/1,068.80 = 279.32/x
  3. Step 3: Cross multiply
    712.40x = 1,068.80 × 279.32
  4. Step 4: Simplify right side
    712.40x = 298,530.48
  5. Step 5: Solve for x
    x = 298,530.48/712.40
  6. Step 6: Final answer
    x = 419.05

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.