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Finding the Fourth Proportional to 430.78, 646.36 and 214.50

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Solution

The fourth proportional to 430.78, 646.36 and 214.50 is: 321.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.78 : 646.36 = 214.50 : x
  2. Step 2: Convert to fraction form
    430.78/646.36 = 214.50/x
  3. Step 3: Cross multiply
    430.78x = 646.36 × 214.50
  4. Step 4: Simplify right side
    430.78x = 138,644.22
  5. Step 5: Solve for x
    x = 138,644.22/430.78
  6. Step 6: Final answer
    x = 321.84

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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.