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Finding the Fourth Proportional to 431.42, 646.59 and 339.76

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Solution

The fourth proportional to 431.42, 646.59 and 339.76 is: 509.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.42 : 646.59 = 339.76 : x
  2. Step 2: Convert to fraction form
    431.42/646.59 = 339.76/x
  3. Step 3: Cross multiply
    431.42x = 646.59 × 339.76
  4. Step 4: Simplify right side
    431.42x = 219,682.19
  5. Step 5: Solve for x
    x = 219,682.19/431.42
  6. Step 6: Final answer
    x = 509.21

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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.