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Finding the Fourth Proportional to 430.10, 643.55 and 256.86

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Solution

The fourth proportional to 430.10, 643.55 and 256.86 is: 384.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.10 : 643.55 = 256.86 : x
  2. Step 2: Convert to fraction form
    430.10/643.55 = 256.86/x
  3. Step 3: Cross multiply
    430.10x = 643.55 × 256.86
  4. Step 4: Simplify right side
    430.10x = 165,300.97
  5. Step 5: Solve for x
    x = 165,300.97/430.10
  6. Step 6: Final answer
    x = 384.34

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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.