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Finding the Fourth Proportional to 499.40, 689.12 and 278.32

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Solution

The fourth proportional to 499.40, 689.12 and 278.32 is: 384.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.40 : 689.12 = 278.32 : x
  2. Step 2: Convert to fraction form
    499.40/689.12 = 278.32/x
  3. Step 3: Cross multiply
    499.40x = 689.12 × 278.32
  4. Step 4: Simplify right side
    499.40x = 191,795.88
  5. Step 5: Solve for x
    x = 191,795.88/499.40
  6. Step 6: Final answer
    x = 384.05

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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.