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Finding the Fourth Proportional to 458.80, 684.22 and 390.76

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Solution

The fourth proportional to 458.80, 684.22 and 390.76 is: 582.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    458.80 : 684.22 = 390.76 : x
  2. Step 2: Convert to fraction form
    458.80/684.22 = 390.76/x
  3. Step 3: Cross multiply
    458.80x = 684.22 × 390.76
  4. Step 4: Simplify right side
    458.80x = 267,365.81
  5. Step 5: Solve for x
    x = 267,365.81/458.80
  6. Step 6: Final answer
    x = 582.75

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.