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Finding the Fourth Proportional to 430.80, 646.35 and 211.51

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Solution

The fourth proportional to 430.80, 646.35 and 211.51 is: 317.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.80 : 646.35 = 211.51 : x
  2. Step 2: Convert to fraction form
    430.80/646.35 = 211.51/x
  3. Step 3: Cross multiply
    430.80x = 646.35 × 211.51
  4. Step 4: Simplify right side
    430.80x = 136,709.49
  5. Step 5: Solve for x
    x = 136,709.49/430.80
  6. Step 6: Final answer
    x = 317.34

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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.