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Finding the Fourth Proportional to 430.56, 646.65 and 257.76

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Solution

The fourth proportional to 430.56, 646.65 and 257.76 is: 387.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.56 : 646.65 = 257.76 : x
  2. Step 2: Convert to fraction form
    430.56/646.65 = 257.76/x
  3. Step 3: Cross multiply
    430.56x = 646.65 × 257.76
  4. Step 4: Simplify right side
    430.56x = 166,680.50
  5. Step 5: Solve for x
    x = 166,680.50/430.56
  6. Step 6: Final answer
    x = 387.12

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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.