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Finding the Fourth Proportional to 430.78, 646.02 and 142.18

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Solution

The fourth proportional to 430.78, 646.02 and 142.18 is: 213.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.78 : 646.02 = 142.18 : x
  2. Step 2: Convert to fraction form
    430.78/646.02 = 142.18/x
  3. Step 3: Cross multiply
    430.78x = 646.02 × 142.18
  4. Step 4: Simplify right side
    430.78x = 91,851.12
  5. Step 5: Solve for x
    x = 91,851.12/430.78
  6. Step 6: Final answer
    x = 213.22

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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.