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Finding the Fourth Proportional to 499.56, 689.40 and 278.55

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Solution

The fourth proportional to 499.56, 689.40 and 278.55 is: 384.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.56 : 689.40 = 278.55 : x
  2. Step 2: Convert to fraction form
    499.56/689.40 = 278.55/x
  3. Step 3: Cross multiply
    499.56x = 689.40 × 278.55
  4. Step 4: Simplify right side
    499.56x = 192,032.37
  5. Step 5: Solve for x
    x = 192,032.37/499.56
  6. Step 6: Final answer
    x = 384.40

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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.