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Finding the Fourth Proportional to 430.71, 646.93 and 257.72

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Solution

The fourth proportional to 430.71, 646.93 and 257.72 is: 387.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.71 : 646.93 = 257.72 : x
  2. Step 2: Convert to fraction form
    430.71/646.93 = 257.72/x
  3. Step 3: Cross multiply
    430.71x = 646.93 × 257.72
  4. Step 4: Simplify right side
    430.71x = 166,723.89
  5. Step 5: Solve for x
    x = 166,723.89/430.71
  6. Step 6: Final answer
    x = 387.09

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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.